More power for 351M

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

guitardave208

New member
Joined
Jan 29, 2006
Messages
13
Reaction score
0
I have a 351M in my 1978 Ford F150 and I am tryin to get more horsepower from it.. Anyone got any suggestions?

 

va92bronco

New member
Joined
Feb 27, 2006
Messages
17
Reaction score
0
I have a 351M in my 1978 Ford F150 and I am tryin to get more horsepower from it.. Anyone got any suggestions?
32916[/snapback]

TRW use to make a flat top piston for the 351 M. The easiest way to make power is to replace the crank and pistons to a 400M. I believe the connecting rods are the same for both motors, but verify with a second source just to make sure. Any 351C aftermarket cylinder heads will work on the 351/400M motor. You have to use a 351/400M intake because of the deck clearance.

The worst problem with the M is the low compression. Ford did this to lower the emissions. If you get the c/r around 9.5 you could have a decent motor, but be careful with the RPM's. I wouldn't push it past 6000RPM.

Hope this helps.

 

erocin 79

New member
Joined
Mar 31, 2006
Messages
3
Reaction score
0
I have a 351M in my 1978 Ford F150 and I am tryin to get more horsepower from it.. Anyone got any suggestions?
I have a 400M in my 79 bronco, and I know the feeling of not having much power..Flat top pistons do help, but if you dont want to tear the engine apart I would suggest an intake, carb, open element air filter, and a true dual exhaust system with a nice set of headers. This setup added quite a bit of power to my truck, but if you want some real power out of that motor, your going to have to ditch those old pistons and camshaft.

 

highboy73

FORDing thru life
Joined
Jan 18, 2004
Messages
259
Reaction score
3
Location
morocco,indiana
is the timing set a aftermarket one?the 351m/400 come factory ******** 4 degrees.a crank sprokect that put's it in straight up will give you a power increase that you can feel.while you got the timing set off...throw a small tq cam in there something around a 262-268.try for a dual pattern more on the exhuast.you could get the heads shaved ...if you go much past .30 you'll need to get theintake done too.

here's a couple sites I found very imformative

http://www.projectbronco.com/Technical_Art...ce_build_up.htm

http://www.off-road.com/ford/flashback/400_power.html

 
Last edited by a moderator:

Captain p4

New member
Joined
Jul 10, 2006
Messages
23
Reaction score
2
Location
Joppa, Maryland.
I'm having the same issues with a slugg 351m. My first purchase was headers/exhaust system to make it sound good at least.

From here, I don't know what I should do next. Cam, timing set, 4barrel intake/carb, shave the heads to get the CR up.. what else can you do to this engine that doesn't involve the bottom end?

 

78 BEAST

New member
Joined
Jul 11, 2006
Messages
13
Reaction score
0
Location
Colorado Springs
Projectbronco.com has a good tech article on the 351/400m rebuild they explain part useage and everything is broken down on the boring specs. To make the 351m into a 400m all you have to do is change the crank and pistons the connecting rods are the same.

 

79highrider

New member
Joined
May 22, 2006
Messages
123
Reaction score
0
Location
Frenchtown NJ
I have a 400M in my 79 bronco, and I know the feeling of not having much power..Flat top pistons do help, but if you dont want to tear the engine apart I would suggest an intake, carb, open element air filter, and a true dual exhaust system with a nice set of headers. This setup added quite a bit of power to my truck, but if you want some real power out of that motor, your going to have to ditch those old pistons and camshaft.
my 79 has an all stock 351m with the stock 2brl carb and is definate need of some horsepower, my grandfather's 1954 ford with all stock 268 cu in or whatever it is v8 sounds better. :-& I was gunna go with intake, carb, k&n air filter, and short tube headers any sugestions on what intakes and carbs go well with this motor? the carb I had in mind was the Holley Truck Avenger with a Holley intake to match.

erocin 79 what intake and carb are you running?

 

BLADE262US

Active member
Joined
Feb 21, 2004
Messages
1,713
Reaction score
5
Location
Michigan
Look on ebay for ford 351C aussie heads should be around $300 to $350 . Then look up 351C stainless valves should find mad dog racing ebay store be able to get full set intake and exhaust for under $150 , have them cleaned up and machined mad dog can hook you up with valve springs too , These are very good heads will bolt right on being that 351C/351M/400 all share same heads but the aussies took it a few steps farther than we did running there version as a 302 cleveland up into the mid 80,s You should be happy with this improvement .

 

79highrider

New member
Joined
May 22, 2006
Messages
123
Reaction score
0
Location
Frenchtown NJ
I went on summitracing.com and looked up intakes and carbs for 351m's and found that holley truck avenger carbs are really expensive and like you said 78 beast I have only heard good things about edelbrock performer series stuff so while I was on I priced a 600cfm edelbrock carb for around $260 and a performer series intake for like $200.

Now what about headers someone in another forum a while back said long tube headers run right into the trans cross member so does that mean stick to short tube headers. What kind of headers are you guys with them using? and what is the price range?

 

Captain p4

New member
Joined
Jul 10, 2006
Messages
23
Reaction score
2
Location
Joppa, Maryland.
I was working on putting my long tube headers on today and they seem to fit pretty well. I got the heddman headers and had no problems with install, i also ordered the ****** exhaust system for it and two magnaflow mufflers, I haven't gotten to the exhaust system yet, but set the pipes in there for a couple seconds and it looks like it is going to line up pretty well for being three different brands of stuff i bought!

I'll let you know how the rest of the install goes.

 

Colorado Bulldog

New member
Joined
Oct 11, 2006
Messages
7
Reaction score
0
I know this topic is fairly old but I'll add my 2 cents.

On my 79 Bronco, it still has the original 351M/400 but it has an Edelbrock performer intake and a holley 600 4 Barrel (guessing on the cfm). I have no idea about the cam size but I kind of think it has the roiginal cam. It doesn't have the fast response that you would get from a performance cam.

With all of that being said, I plan on doing one of a few things. If I keep this motor, then I plan on boring it out at least .030 over, porting and polishing the heads, setting forged pistions and rods in it, and going with a full roller cam, lifters, rockers, and pushrods. For the exhaust, I'll be putting in headers with either flowmaster or terminator mufflers. By the time I get done with the motor alone, I figure at least $4000 worth of work. What I just mentioned will probably give this motor a ton of power.

If I decide on a motor change, I'm going with a 390 and doing the same thing to it. Either way, my bronco will be a bad boy on the trail.

 

Members online

No members online now.

Latest posts

Forum statistics

Threads
22,509
Messages
135,879
Members
25,108
Latest member
Utahstroke
Top