Chevy/GMC Trans

[maxx]

I have a 1987 GMC V3500, his name is Private Pyle. Currently has a TBI 350, Turbo 400, NP205, 14 bolt rear, 60 front, H2 wheels with 315/70/17 Duratracs.

I'm not sure what gears it has in it, but they are very deep. I don't have a tach on it but it's wrapped out pretty good at 60-65 even with the big tires on it.

I'm looking at putting a transmission with overdrive in. What are my options here? looking for info on the complete package. What will bolt up, what will I need to do for a crossmember, will current drivelines work, how do I control the tranny, etc.

Basically what I'm looking to see, is can I make a 700r4 work. Can I basically bolt one in and go. What kind of limits will it have, what kind of upgrades should I do?

 

[crash2]

The only problem with a 700r4 is you will be downgrading in strength and I am not certain whats available to mate the NP205 to it. I would look at a 4l80e with a stand alone computer since they are electronically shifted and you will still retain the same strength since I know a NP205 can be mated to it.

Any of the OD tranny's(700r4/4l60e/4l80e) will be longer than the TH400 so you will have to rework the x-member and driveshafts.

 

[maxx]

good to know on the crossmember/driveshafts.

I'd love to go for the 4l80e route, problem is a standalone controller is like $700 by itself.

I don't mind doing some upgrades to the tranny. Basically I just want to make it a little nice for when I go on longer drives. If I use it to tow I can just pull it out of OD which leaves me in the same boat as the TH400.

 

[maxx]

Advance adapters claims the TH400 is actually longer, but by less then an inch

 

[boardbysled]

What about a 5 speed swap? May as well do a Cummins why your at it.:fawkdancesmiley:

 

[Jeepasaurusrex]

I have a T-5 5 speed you can have :fawkdancesmiley:

 

[crazybluerider1]

I understand that you can use the factory 6.2/6.5 diesel trans controller as a stand alone unit for the 4l80's. If you can find it and a harness I have read that it is fairly easy to make it into a stand alone controller for an app like yours.

 

[maxx]

What about a 5 speed swap? May as well do a Cummins why your at it.:fawkdancesmiley:

Would love to do a nv4500. But I'm looking for cheap and simple.

And the cummins would suck with the current gearing!!!

 

[maxx]

I understand that you can use the factory 6.2/6.5 diesel trans controller as a stand alone unit for the 4l80's. If you can find it and a harness I have read that it is fairly easy to make it into a stand alone controller for an app like yours.

Veeeeery interesting. I think the early ones were a turbo 400, didn't think about a later model though.

 

[Corey Y]

Cheap and simple would be a $300ish Spicer Brownie OD off Craigslist or a junkyard. A stock, core 4l80e/205 will be about $1000 if you can find one, and you would still need a controller or manual valve body.