This is mainly for those of you whom I confused back a couple of months ago. Someone asked me a question regarding the 3-speed to NP435 swap and I forgot what I said and when I went back to read my postings, I read that what I posted was wrong. Here is an amendment to the actual installation. Please follow these guidelines and not the original ones I provided back in November or so. My appologies to anyone who has had a setback for my error.
This guide is intended to get around having to buy an adapter from somewhere like Advanced Adapters or other parts warehouses. It is also intended to save you some money, as with this set up you can easily do it for less than $1,000.00 where as if you buy the entire setup from a Bronco company it can cost up to or even past $1,250.00.
NP435 swap:
The bell housing & x-fer case will stay the same. You will also be able to keep your original driveshafts with this conversion. The things you will need to obtain are an adapter from a 6 cylinder engine and an NP out of a 2wd truck.
This particular conversion will only work if you get a transmission with a square 4 bolt pattern and is out of a 2wd truck. Use one from a 67-83 Ford truck F100-350 with a small blocks engine. It must be 28 spline output shaft with square tail housing bolt pattern. They may also be found bolted up to 360 & 390 c.i. engines.
There are other NPs out there that are an offset pattern and if you get one of these you will have to get the adapter plate to make it work. Also the 4wd trans will not always work because of the length of the output shaft, they are usually longer than the 2wd and will need to be replaced. If you do find one in a four wheel drive, it should be one that is bolted directly to the transfer case because they typically have the correct output shaft
INSTALLATION:
1. Unbolt the trans/adapter/x-fer from the vehicle.
2. Save or replace the 4 old transmission/x-fer case mounting washers and remember which goes on top and which one is on the bottom of the cross member. They are 2 different sizes, 1 is a thick washer and the other is a thin one.
3. Break the x-fer away from the adapter & trans and get them out of the way.
4. Take the new 6-speed adapter and bolt it to the NP transmission.
5. Bolt the x-fer to the new adapter/trans combo.
6. Take your old/new x-member washers and swap their positions. By this I mean move the thick ones to where the thin ones were and vice versa. If I remember correctly, the thick ones will now go on the bottom of the x-member and the thin ones will go on top.
7. Bolt the x-member to the trans/adapter/x-fer.
8. Bolt everything up into place.
You will not need to get new driveshafts as this setup is within +/- 1" of the old set up and the slip in the driveshafts will be able to compensate for this change. Finding the transmission can be difficult, but you can get them for less than $400 out of junk yards if you pull them yourself. About the only thing that will be out of grasp is the adapter because in most cases, if the donor Bronco was in a junk yard, it will probably be pretty well picked over. For this you might need to order one from one of the supply companies. For this I would recommend going with BC Broncos in Hesperia, CA http://www.bcbroncos.com/store/ because they are pretty darn reasonable for the 6-speed adapter at around $150. Like I said before, you can do this for less than $1,000. I did it for less than $800, and the majority of that was for a rebuilt transmission.
Again, I apologize to anyone whom I misled in my previous postings regarding the NP435 swap and I hope that this will help out to those of you who are doing this install currently.
This guide is intended to get around having to buy an adapter from somewhere like Advanced Adapters or other parts warehouses. It is also intended to save you some money, as with this set up you can easily do it for less than $1,000.00 where as if you buy the entire setup from a Bronco company it can cost up to or even past $1,250.00.
NP435 swap:
The bell housing & x-fer case will stay the same. You will also be able to keep your original driveshafts with this conversion. The things you will need to obtain are an adapter from a 6 cylinder engine and an NP out of a 2wd truck.
This particular conversion will only work if you get a transmission with a square 4 bolt pattern and is out of a 2wd truck. Use one from a 67-83 Ford truck F100-350 with a small blocks engine. It must be 28 spline output shaft with square tail housing bolt pattern. They may also be found bolted up to 360 & 390 c.i. engines.
There are other NPs out there that are an offset pattern and if you get one of these you will have to get the adapter plate to make it work. Also the 4wd trans will not always work because of the length of the output shaft, they are usually longer than the 2wd and will need to be replaced. If you do find one in a four wheel drive, it should be one that is bolted directly to the transfer case because they typically have the correct output shaft
INSTALLATION:
1. Unbolt the trans/adapter/x-fer from the vehicle.
2. Save or replace the 4 old transmission/x-fer case mounting washers and remember which goes on top and which one is on the bottom of the cross member. They are 2 different sizes, 1 is a thick washer and the other is a thin one.
3. Break the x-fer away from the adapter & trans and get them out of the way.
4. Take the new 6-speed adapter and bolt it to the NP transmission.
5. Bolt the x-fer to the new adapter/trans combo.
6. Take your old/new x-member washers and swap their positions. By this I mean move the thick ones to where the thin ones were and vice versa. If I remember correctly, the thick ones will now go on the bottom of the x-member and the thin ones will go on top.
7. Bolt the x-member to the trans/adapter/x-fer.
8. Bolt everything up into place.
You will not need to get new driveshafts as this setup is within +/- 1" of the old set up and the slip in the driveshafts will be able to compensate for this change. Finding the transmission can be difficult, but you can get them for less than $400 out of junk yards if you pull them yourself. About the only thing that will be out of grasp is the adapter because in most cases, if the donor Bronco was in a junk yard, it will probably be pretty well picked over. For this you might need to order one from one of the supply companies. For this I would recommend going with BC Broncos in Hesperia, CA http://www.bcbroncos.com/store/ because they are pretty darn reasonable for the 6-speed adapter at around $150. Like I said before, you can do this for less than $1,000. I did it for less than $800, and the majority of that was for a rebuilt transmission.
Again, I apologize to anyone whom I misled in my previous postings regarding the NP435 swap and I hope that this will help out to those of you who are doing this install currently.
