350 TBI swap with a 4L60E Questions (1 Viewer)

[baja1d]

I've got an opportunity to buy a complete donor truck and do a 350 TBI swap with a 4L60E automatic tranny in my 40 but have a couple of questions:

1. Does it make a difference if this 4L60E is two wheel drive or 4? This particular one is 4x4.
2. AA sells a adapter to use my split case but in my "quest for information" (yes, I've spent the last few hours searching) some have mentioned cutting the rear shaft of the 4L60E. I can't find any info on AA website but which is correct?
3. I began searching with a dry tee shirt but now it's full of drool and I want a doubler. I was thinking NP203 but it looks like AA only sells a NP205 adapter. What’s the deal? BTW, I plan to fab most of brackets and avoid the $$$ for AA if I can. I say this because I'm not afraid to get down and dirty but I've used their site for reassurance that my combination will work and not be left with a few bloody knuckles.
4. Linking & 1 tons are also on my radar. Should I just plan on using the 4L60E, NP203 or 205, & Chevy T/C from the get go or go through the trouble of making my 40 axles w/ cryo'd shafts work?
5. Please forgive my chevy ignorance!!!

This rig is in pieces, the previous owner had hundreds of hours tied up in disassembly & cleaning every up. It will be a DD and see many trips to Moab. To date, I've wheeled my rigs to their abilities and it's a matter of time before I'm in over my head with the wrong rig!!! With that being said, here's the state of my "second 40 build" as it sits. IMO the possibilities are endless. Unlike my constantly changing first 40 build, I'd like this one to be done start to finish with ONE plan in mind... whichever plan/combo that maybe. Oh yeah, the crawl box is in my first 40.

 

[Gumby]

4l60e with a 203 doubler is long in a 40. When mine was in my 40 the driveshaft was barely longer than the stock slip yoke. It can be adapted to a Dana 300 which has 4:1 options, or, of course, an atlas.

Put longfields in the stock axles and call it good. Even if you go with a centered output you can do a mini cruiser hybrid rear and be plenty strong.

 

[chicago]

I did it...

It's a LOT of extra work to make it fit.
Had to re locate the rear axle as far back as I could go w/ it, relocate the fuel tank... I ended up building my own and putting it under the rig and of course had to modify the floor pan and the trans tunnel.
That being said, I LOVE THE SET UP!!!
I have a 27 in rear DS, so the extra work was worth it.
Mine is the 5.3 vortec, 4l60e, 203 GRB/ split case.

 

[baja1d]

I did it...

It's a LOT of extra work to make it fit.
Had to re locate the rear axle as far back as I could go w/ it, relocate the fuel tank... I ended up building my own and putting it under the rig and of course had to modify the floor pan and the trans tunnel.
That being said, I LOVE THE SET UP!!!
I have a 27 in rear DS, so the extra work was worth it.
Mine is the 5.3 vortec, 4l60e, 203 GRB/ split case.

This was the source of most of my drool! What's this Dana 300 all about?

 

[Gumby]

Very good 80-86 jeep transfer case with lots of aftermarket support.

http://www.novak-adapt.com/catalog/adapters/transmission_to_transfer_case/kit_137.htm

http://www.novak-adapt.com/catalog/shifters/kit_low300.htm

 

[pb4ugo]

Does the 4l60E have a t/case on it now? If so what is it?

 

[baja1d]

Does the 4l60E have a t/case on it now? If so what is it?

Yes it does but I'm not sure which one

 

[pb4ugo]

What side is the frt ouput? Is the case aluminum? You probably need to id it. As you know when changing drive lines there are many directions to go. Do you want to keep the offset axles or go with centered pumpkins?

 

[chicago]

Sorry...last night, the post and the questions DID NOT come up...
The deal w/ the 2wd vs. 4wd shaft is that the 2wd shaft is LONGER. the 4wd shaft is too short to engage fully into the 203. What that means (unfortunately) is you will need to REPLACE the output shaft on the trans OR get a 2wd trans. The 2wd shaft you can CARFULLY cut to the appropriate length. HOWEVER....the 4L60E transmissions DO HAVE an issue in the valve body that can be corrected if you decide to replace the shaft. The issue is one of the STEEL solenoids (constantly energized when running) that is in an ALUMINUM valve body. The wear on that valve body can cause the ECU to detect a problem and it will go into "limp" mode. What I found out that this can occur as early as 60K miles. What they do is drill out the VB and put a steel sleeve in. For me...I just had the whole trans re built and completely gone through just for piece of mind.
As far as the split case to 203 adapter...Jerry Nichols at colorado off road express is the man that sells and designed these. AA makes them for him. I think theyre around 500 bucks.
I really considered an Atlas, but they were too cost prohibitive for me. Admittedly, it would have been a TON EASIER route to go, but I was also staring down the barrel of replacing the rear axle or buidling a hybrid centered rear... replacing the axle and the cost of a 3 speed atlas was gonna end up being around 5 or 6 K when you factor in EVERYTHING!
AA sells the new output shaft for the trans.
I think that Marlin sells a toy box to go in front of the split case now?? I think its around 1300 or so...
As far as mating the trans to the 203, AA sells a new tail shaft housing which you will likely want a VSS. At least thats what I needed to make the vortec work and jive with the computer.
Its a LONG ROAD to haul, but you LEARN so much in the process and in the end....theres NOTHING (virtually) about your rig you DONT KNOW!
I dont know what you have for axles, gears and lockers and FUNDS, but the ATLAS 3 speed and a centered rear would make life INFINITELY easier. I just could NOT justify the expense of it.
If youre looking at a re gear for both axles any way, you might consider a shaved 14 bolt. Youll have to do some cutting and welding on the axle to bring the WMS's in, but theyre STUPID strong and cheap to get. Down side is theyre heavy and the pumpkin is HUGE. If youre not running 40 in tires youll be draggin it.

 

[baja1d]

Thanks guys for all the info. On one hand I'm really excited to do something different but, on the other hand, it's a bit overwhelming. I wish I had more info but this is all I have from his CL posting:

1994 GMC Chevrolet truck for parts or repair. Not selling small parts off it at this time. The truck is complete but there is no title. Buy it for parts or bond for title and drive it. It has a TBI 5.7 liter (350) engine that starts and runs well. 4L60E automatic trans works well as does the four wheel drive. Odometer shows 219k but this was origianlly a well maintained county owned truck.. It's a plain jane model with A/C and rubber floor mats. No rust but there are some dents along the right side. Tires are worn and the brakes are soft like it needs a wheel cylinder or master cylinder.

 

[mookie]

If your planning to put tons in it anyway then do yourself and your wallet a big favor and go all chevy on the drivetrain

And thats probably a np241 behind the 4l60e your looking at

You might want to look into this kit, lets you use the front half of a np231 or 241 and double it with a d300 or a np205 behind it

http://www.pirate4x4.com/forum/moto...31-planetary-crawlbox-box4rocks-499-a-18.html

 

[baja1d]

Why is it so hard to make a decision? I guess I'm looking for a "one & done" senerio since I'll have no dirt and grease to deal with. I know that they'll be repairs along the way but I definitely don't want to be swapping axles, or tranny, in two years because they're not holding up. What do you guys think about a mild 350, 4l60, atlas (Marlin or Orion), Toyota split case with FJ axles and long fields? I ask because I have most of this now.

 

[pb4ugo]

I'm in the middle of a D & D np231/d300 kit & flipping the D300. Were putting it in my nephews YJ. The kit is pretty cool. Because of the length, I don't think it would work w/a offset rear axle unless the axle is moved way back. Were having to move the driveline forward & stretch the rear, The vehicle is SUA which is different than most have done w/this setup.

I think the OP needs to really decide what the end product will be when he's done,(offset rear or not, drivers side drop frt or pass, 1 tons or L/C, etc) or else your just going to be chasing $$ down the road, then he figures out he made the wrong choice in the beginning. I have a friend who rebuilds trannys, &
I know he works on a lot of 4L60E's. 214k is alot of miles.

 

[mookie]

I run a stock 350 and i have broken (and am systematically replacing) every single peice of my toyota drivetrain with it, i would give anything in hindsight if i had just done all chevy from the get-go

 

[baja1d]

I run a stock 350 and i have broken (and am systematically replacing) every single peice of my toyota drivetrain with it, i would give anything in hindsight if i had just done all chevy from the get-go

That's exactly what I want to avoid. It's looking like all Chevy with a Atlas 4.3

 

[chicago]

I've wheeled my stock rears for one season w no issues as of YET.
IF the do become an issue, then I'll be looking into upgrades.
I'm pretty light on the skinny though.

 

[mookie]

If 3:1 is low enou gh for you then Check out the lomax too, jb conv is about to start selling them again

 

[baja1d]

One tons it is. Just purchased a pair today!

 

[GLTHFJ60]

This is gonna be a fun build.

 

[Tigerstripe40]

ft for the trans.
I think that Marlin sells a toy box to go in front of the split case now?? I think its around 1300 or so...

I've been jonesin' for an SM420-ToyBox-SplitCase for a while now....

It's posted on the web site as 'pricing and information coming soon' but hasn't been available for well OVER a year now....

I am thinking that by the time its available, I till have bought and paid for a 4 Speed Atlas, and built some sort of centered rear end (I am actually thinking an 8.4" Taco rear end -its good enough for the tundra's).