New to this world so looking for some advice.

I started a project rat rod recently, a late 40's Chev truck, and was on the hunt for a motor. Originally was looking for a Gen III 2WD truck but came across a 2007 3500HD with a Gen IV LY6 to cheap to pass up. Bought the entire running truck so I have all the parts I should require to get the motor going.

The problem I'm having is that the transmission that came with it of course was a 6L90e 4x4 which won't work I need a 2WD. So I was trying to source a 6L90e 2WD but then talking with some friends a few suggested I abandon the 6L90 altogether and focus in on a TH400, old school that can easily be built to handle all the power I could ever pump out of the LY6. So I've been looking at some various TH400's but all seem like junk, there is also a pile of TH350's that again from what i've been told can be built up to handle a decent amount of HP.

So I've been kindof geared towards a TH350 or 400 but now came across a 4L80e with a standalone controller, I believe it's an older model TIC built by Fast model 301002, found a couple people online running them and they don't seem like a bad controller.




So this is where my confussion and question stem from.. what would be some pros/cons going with any of these transmissions? The older TH350/TH400 I would assume easier to install and configure (although would require likely new flex plate etc) the 4L80e being it has already a stand alone controller seems like a nice option and gives me some new controls/features


Which way would you guys go with the build? I'm not looking for 1/4 mile monster, more a fun daily driver that I can rip around the streets and roast the tires whenever I feel the need.

 

The guy with the 4L80e and standalone controller is looking for $800 it's apparently stock with about 60K miles, there is another with a TH400 rebuilt a few years ago but very little use since with a stage 2 shift kit plus deep oil pan plus a Hughes 3500 torque converter for $1K

Those are my 2 best finds thus far... I'm assuming I can sell the 4x4 6L90e and transfer case and cover the costs for either option

 

Some of the vans come with the LY6 with the 4l80 trans, I'm not by any means a resource so please read. I think you can get your truck E38 reprogramed and add a gm tcm. Maybe find a van harness. Overdrive is worth the extra work.

Start reading in the conversion section

 

Go with a 4l80 have someone reprogram e38 to run 4l80 . When I was doing my swap psi conversions was very helpful . They sell harnesses, ecms, programming etc..

 

If transmission size isn't an issue for you, the 80e is the way to go. Very strong transmission but it's a bit on the obese side.

I echo jimmyg's sentiment about PSI. I used them and they have been responsive/helpful with high quality products.

 

I don't think size will matter much to me, any of the vehicles at the farm I have plans for basically all are trucks and older ones, with either a pile of room to begin with or else I don't mind cutting the floor to make some extra room if need be.


I've read many guys saying PSI is the way to go, checked out their site a number of times. Maybe I should contact them and see what they recommend.


If I went the way of reprogramming the E38 controller, is that something that can be done with EFILive or HPT? Or best to simply send it off to the pro's and sit back and let them figure it all out? I've always been a heavy DIY'er but being this is my first vortec donor this is all new to me, but have to learn somewhere!