MORE PERFORMANCE

[ALL LAND]

Hi everyone I'm new to this site and have been an early Bronco lover for more than 40 years. I was just a boy on a BMX bicycle when I saw a red and white Bronco (about a 72) and was instantly in love. I said when I grow up I'm going to get one of those broncos. I was about 19 years old and took all of my life savings and bought a 1976 green Bronco. This Bronco was totally stock when I bought it. What I did - Two and a half inch coil lift 1 inch body lift dual steering stabilizers 33x12.5 -350 gears Double Shock Rancho front, add a leaf in the rear to make it level rebuilt leaf springs all new bushings rebuilt 3-speed manual converted to the floor Extra heavy duty clutch, high performance hearst shifter rebuilt engine, ring and pinion + axles, custom drive shaft, huge power amplifiers 4 speakers two subs. Backseat boneyard mini Chevy Blazer back in the day, it fits with minor modifications.

I love this truck and have owned it more than 33 YEARS !
It was the
first year of power steering power disc brakes, updated different front end, electronic ignition the only downfall is it has smog here in California. At first it didn't bother me too much as it was good enough for the time however, I would like to have some more performance and thinking about just making it an off-road Bronco and maybe keeping it where I can quickly convert it for the street if I need to. The shop that built my Bronco here in California told me that the four barrel and intake would not make that much difference. I would like to do something with a quick swap but the 76 motor choked with smog and a small two barrel I'm very limited. I've been reading about a small blower on a stock bottom end I know that would help ( and still willing to do) My rebuilt 302 passed with a VERY LOW smog emissions that I have a huge amount of more smog that I could produce and still pass. So, maybe a high performance ( 350 HP Crate motor ) on the bottom and then to be smog legal use stock 2BBL and intake + pump to pass. Would it work ? would the lift on the cam be too much ? I am on a budget so the crate motor at $4500. is a little too much but still an option.
I guess what I'm looking for is a quick performance swap on this 76 smog Bronco thanks in advance for all your help !

 

[Carnutt73]

The biggest problem i have found on those early smog engines is the cam and intake. A good cam will liven up the engine alot but do not go any more than a .479 lift with a 110 lobe separation if you are keeping the stock compression in the engine. A good intake would be an edelbrock performer rpm air gap. Though i am not sure if the intake and carb would fit under the stock hood. This is a good all around set up i have used before and works very well. I would say to call comp cams and talk to one of their reps and they can steer you to a good cam setup that will work with what you want to do and stay smog legal. Edelbrock intakes are 50 state legal so you should be good there..

 

[chrlsful]

incrementally is my answ.
Just turn up the timing a few degrees past stock. Some R happy there. Get DSII ignit parts if not. Still not happy onto a carb up grade, etc. Rockers would B B4 cam by if U must go on, sure thats nxt, etc, etc.

 

[miesk5]

Yo ALL LAND,
WELCOME!
As CHRISFUL advised on the timing and others can provide some smog friendly upgrades.

 

[Tiha]

A clean burning engine produces less emissions. A efficient engine burns clean. Performance enhancements usually make an engine more efficient.

To see real gains you are probably going to have to find a different set of heads. Better flow, bump the compression a little. Then a cam and intake. Correct the timing. Those old 2 barrel carbs would flow plenty of cfm. Back in the day we used to get 2 barrel aluminum intakes.

All the work I did on mine I was never impressed with the horsepower gains, but the torque was pretty amazing.

 

[ALL LAND]

First a quick thanks to 73, Chrisful, Miesk5 (Thanks for your service) and Tiha. You Guys Rock ! Yes I have advanced the timing. Has anyone see the performance bump from the stock 2 BBL to a 4BBL maybe 600-650 ? About how much of a bump would this give ? The guys here in Cali. said "It's not as much as you think "
Would the .479 cam be too much to pass smog with the stock 2BBL ?

My emissions were so low that I have a huge buffer that I could put out more and still pass smog. So Beef cam, on the bottom with stock heads ? Would the aftermarket aluminum heads and Beef cam pass smog ? I would like to keep it somewhat simple. Obviously the blower won't pass but that would be when it's off road.

Anyone know anything about a small Blower on a stock bottom end ? Been reading up on this and they say it works. I would like to see at least 60-80 Bump in HP. Remember, a bolt on solution that's quick and removable. I just wanna bang the gears and be thrown back in the seat, I know everyone knows this feeling
THANKS !

 

[Jasgeer]

I agree with many of the statements which have been made by readers but will add a different perspective. If you want to add a notceable injection of power then here are my thoughts.

You lose a lot of power applied over your range by only having a 3 speed transmission. If you were to have a 5 speed then each gear would tach up much quicker and the car would feel faster. The only thing worse than a 3 speed would be a 2 speed. I have a 5 speed ZF trans out of an 80s to 90s F150 and Broncos. The low first gear is probably lower than any of your and the 5th gear is OD wich enabled me to use hight numerical ratios in the differentials. Again, the engine feels stronger.

Torque is king. A torquey engine feels like it wants to move. Adding a stroker crank kit to your 302 would add directly to the bottom end. It is unfortunate that you already rebuilt your enine and probably used the same vintage 302 block. Blocks after about 1986 had roller cam followers cast into the block as opposed to flat tappets. With a roller cam you can add appreciable low end power and yet not lose vacuum. The valves open and close much more quickly. This is called more time under the curve. The longer the valves are held open can translter into more HP. If you have ever driven a 1985 to 1996 Ford Mustang 5.0 compared to earlier years you can feel the difference made by a roller cam, better flowing heads, improved carburation, etc. Explorer 302 engines from the mid 1990s are sought after for Bronco conversions.

 

[Carnutt73]

First a quick thanks to 73, Chrisful, Miesk5 (Thanks for your service) and Tiha. You Guys Rock ! Yes I have advanced the timing. Has anyone see the performance bump from the stock 2 BBL to a 4BBL maybe 600-650 ? About how much of a bump would this give ? The guys here in Cali. said "It's not as much as you think "
Would the .479 cam be too much to pass smog with the stock 2BBL ?

My emissions were so low that I have a huge buffer that I could put out more and still pass smog. So Beef cam, on the bottom with stock heads ? Would the aftermarket aluminum heads and Beef cam pass smog ? I would like to keep it somewhat simple. Obviously the blower won't pass but that would be when it's off road.

Anyone know anything about a small Blower on a stock bottom end ? Been reading up on this and they say it works. I would like to see at least 60-80 Bump in HP. Remember, a bolt on solution that's quick and removable. I just wanna bang the gears and be thrown back in the seat, I know everyone knows this feeling
THANKS !

The engine i finished for my friend is a mostly stock bottom end 302 with flat top pistons, .479 lift crane cam, stock heads with mild porting and stock valve train with a performer rpm air gap intake and 650 cfm carb with msd ignition, and headman headers. The gain was about 90-100 horse. The lower end was rebuilt by someone else before it came to me and he said it was a dog and felt like it had no power. The cam and intake solved it. If you want to keep the 2 bbl i would drop the cam to .433 on a 110 to 112 lobe separation. You gain power in the cam by increasing lift (how much the valve is open) and duration (how long the valve is open for) and the lobe separation just aids in how fast the intake starts to open as the exhaust closes. A .479 lift cam is about as big as you would want to go if using the stock valve train. As far as smog goes the more efficient the engine gets the less smog it produces. That can be handled with a good ignition system and timing and carb tuning. A little bigger cam on a stock engine has very little effect on smog unless the engine can not get enough air and is not properly tuned. Remember how the car companies dealt with emissions back then was by lowering compression and detuning the engine with the cam and timing. Now with all the modern parts available it is easy to bump the engine back up without much effect on smog. I would still say to call comp cams and talk to them. Tell them what you have and what you are trying to do and they can steer you in the right direction. As far a a 2 bbl vs 4 bbl if you put the 4 bbl on with out doing anything else you would see very little gain. Edelbrock sells a package the you can buy that comes with cam and intake and another that also comes with heads. I think they are smog legal but i would have to do alittle checking into it. Now for boost. The stock bottom end can handle a super charger as long as you don't go crazy. I have heard of 302s hitting 500 horse on boost with stock bottom ends. Sadly the are no quick bolt on thing that i am aware of to see a quick 60 to 80 hp gain. Hope this helps a little.

 

[BIG ACE]

First a quick thanks to 73, Chrisful, Miesk5 (Thanks for your service) and Tiha. You Guys Rock ! Yes I have advanced the timing. Has anyone see the performance bump from the stock 2 BBL to a 4BBL maybe 600-650 ? About how much of a bump would this give ? The guys here in Cali. said "It's not as much as you think "
Would the .479 cam be too much to pass smog with the stock 2BBL ?

My emissions were so low that I have a huge buffer that I could put out more and still pass smog. So Beef cam, on the bottom with stock heads ? Would the aftermarket aluminum heads and Beef cam pass smog ? I would like to keep it somewhat simple. Obviously the blower won't pass but that would be when it's off road.

Anyone know anything about a small Blower on a stock bottom end ? Been reading up on this and they say it works. I would like to see at least 60-80 Bump in HP. Remember, a bolt on solution that's quick and removable. I just wanna bang the gears and be thrown back in the seat, I know everyone knows this feeling
THANKS !

Hey all land,
Aside from upgrades with timing,intake,ignition coils,carburetor,cam.Let’s not forget what a more powerful alternator,bored heads for more flow and header for exhaust. Turbocharge can assist as well.

 

[Ray Demanche]

Hi everyone I'm new to this site and have been an early Bronco lover for more than 40 years. I was just a boy on a BMX bicycle when I saw a red and white Bronco (about a 72) and was instantly in love. I said when I grow up I'm going to get one of those broncos. I was about 19 years old and took all of my life savings and bought a 1976 green Bronco. This Bronco was totally stock when I bought it. What I did - Two and a half inch coil lift 1 inch body lift dual steering stabilizers 33x12.5 -350 gears Double Shock Rancho front, add a leaf in the rear to make it level rebuilt leaf springs all new bushings rebuilt 3-speed manual converted to the floor Extra heavy duty clutch, high performance hearst shifter rebuilt engine, ring and pinion + axles, custom drive shaft, huge power amplifiers 4 speakers two subs. Backseat boneyard mini Chevy Blazer back in the day, it fits with minor modifications.

I love this truck and have owned it more than 33 YEARS !
It was the
first year of power steering power disc brakes, updated different front end, electronic ignition the only downfall is it has smog here in California. At first it didn't bother me too much as it was good enough for the time however, I would like to have some more performance and thinking about just making it an off-road Bronco and maybe keeping it where I can quickly convert it for the street if I need to. The shop that built my Bronco here in California told me that the four barrel and intake would not make that much difference. I would like to do something with a quick swap but the 76 motor choked with smog and a small two barrel I'm very limited. I've been reading about a small blower on a stock bottom end I know that would help ( and still willing to do) My rebuilt 302 passed with a VERY LOW smog emissions that I have a huge amount of more smog that I could produce and still pass. So, maybe a high performance ( 350 HP Crate motor ) on the bottom and then to be smog legal use stock 2BBL and intake + pump to pass. Would it work ? would the lift on the cam be too much ? I am on a budget so the crate motor at $4500. is a little too much but still an option.
I guess what I'm looking for is a quick performance swap on this 76 smog Bronco thanks in advance for all your help !

Hey
I always get the 302 out of a 1997-2000 mountaineer the 8th digit on the vin # is P . It has GT40P heads you can use all of your top end. Its 350HP. I put a E303 cam in mine makes almost 500HP in my 89 Bronco

 

[69Lover]

I suppose a question that hasn't been addressed is, Where do you want to focus the power, bottom end with torque or top end with speed? I am running GT40 heads and a Cower Baja Beast cam. I just purchased the Holley Viper efi that I am going to install soon. The engine e was built for me through a gent that worked for Motorsport Team Green racing. His comment about using the GT40'S made sense to me. "One of the largest issues with SB Ford's is that they are restricted breathing because of the size of the exhaust port in the stock heads " we shall see, it will be on the road this fall.

 

[ALL LAND]

WOW ! You guys are great. I'm sad that I invested all that money in the stock low compression block to rebuild ( around 8-1) Although is it worth it to keep it numbers matching ? I have looked at summit racing crate motors with 350HP, that would easily turn my 33's with 350 gears ( I know it's a little too high but low RPM on freeway). I wonder if I could chock this motor with the smog pump and small 2BBL to pass smog as I had a huge buffer of low emissions on my stock motor. Of course I would keep it an off road truck when I go back to the 4BBL and performance parts. So it would be dual purpose, Smog Legal 2BBL with pump. Then Performance Bronco with 4BBL for off road only. Question -First, I want to be legal. Would the performance 350 HP crate motor pass Smog if stock 2BBL, smog pump and all other smog stuff were installed ? THANKS GUYS U ROCK !

 

[Tiha]

I never had to worry about smog so can't help with that one.

Numbers matching, well are you planning on selling it? passing it down to your kids? That is what matters.
If you are not restoring it to factory original then numbers matching really doesn't matter. Some of the highest priced broncos out there have EFI conversions.
I plan on keeping my bronco forever, I know my kids want it pretty bad. I have a list of all the mods and parts I used in the glove box so they will know how to fix it after I am gone or can't remember anymore.
I have a car I thought I would keep numbers matching but the block had enough surface rust the VIN was no longer legible on it. After pouting about it for a little bit I found it rather freeing to not have to worry about such things and just have fun with it.
comparatively 1 in 10 buyers will care about numbers matching and even then it doesn't seem to affect price.

 

[69Lover]

My sentiments exactly. Keeping this thing for as long as I am able to drive. I bought the 69 back in the late 80's in San Diego and garaged it for nearly 30 years. Just had other things get in the way and finally recouped financially enough to move forward

 

[chrlsful]

a bronk is nota race car. Whadda ya want? Still on my applications Q.
I see coyotes ina bronk. Ridiculous to me.

 

[Jasgeer]

WOW ! You guys are great. I'm sad that I invested all that money in the stock low compression block to rebuild ( around 8-1) Although is it worth it to keep it numbers matching ? I have looked at summit racing crate motors with 350HP, that would easily turn my 33's with 350 gears ( I know it's a little too high but low RPM on freeway). I wonder if I could chock this motor with the smog pump and small 2BBL to pass smog as I had a huge buffer of low emissions on my stock motor. Of course I would keep it an off road truck when I go back to the 4BBL and performance parts. So it would be dual purpose, Smog Legal 2BBL with pump. Then Performance Bronco with 4BBL for off road only. Question -First, I want to be legal. Would the performance 350 HP crate motor pass Smog if stock 2BBL, smog pump and all other smog stuff were installed ? THANKS GUYS U ROCK !

All Land, like you I live in the overly regulated state of California and it is my understanding that all gas vehicles 1976 and newer must be smog compliant with what was originally manufactured in the model year of the vehicle. You legally cannot change the cam, exhaust or carburation of a 1976 or newer vehicle unless all of the components are CARB certified as being compliant. If the vehicle were a 1975 then the only limit would be your bank account but as of 1976 you are stuck under the California rules. No changes unless they are certified by California. Adding a turbo or supercharger is verboten unless they were sold in California in that model year. Yes, you can break the law but you run the risk of an envious friend turning you in and California confiscating your beautiful 1976 Bronco.

 

[chrlsful]

Gettin as bad as the TSU in Germany. No wonder all the MT plates in Cali. Hot rods, rat roda, rest0mods? very difficult to impossible over there...
Always a way around it - but U know what - I'd rather see these pretty much OEM (mostly minor "sleeper" mods for comfort, safety, performance). The "P" wrd means MPGs & pep. When the EVs come on strong (can't wait for my price range) I'll jack it up & just use off rd. There anything goes, just don't drive on the asphalt 8^0

 

[johnnyreb]

All Land, like you I live in the overly regulated state of California and it is my understanding that all gas vehicles 1976 and newer must be smog compliant with what was originally manufactured in the model year of the vehicle. You legally cannot change the cam, exhaust or carburation of a 1976 or newer vehicle unless all of the components are CARB certified as being compliant. If the vehicle were a 1975 then the only limit would be your bank account but as of 1976 you are stuck under the California rules. No changes unless they are certified by California. Adding a turbo or supercharger is verboten unless they were sold in California in that model year. Yes, you can break the law but you run the risk of an envious friend turning you in and California confiscating your beautiful 1976 Bronco.

One way you can break the law and they won,t do anything to you. Become a politician.