87 V10 LS

[throttle out]

I'm in the process of gathering all the goodies to do a resto an LS swap on my 87 V10. My truck currently has a 5.7 TBI 700R4 208 combo. I've already purchased a 99 LM7 engine with harness, ECU, and all accessories. I have done an immense amount of searching and research but I'm still on the fence about some things, chiefly of which trans to go with and the pros and cons on each. My plan is to restore the truck, do the drive train swap, and run it for a year or so to see whats what. At that point I would like to install a T70 turbo. This where I know the 4l60 is not going to survive, and feel I need to go 4l80. I understand either trans will need a VSS signal. The 4l60 has its pros for me because I can (if my research serves me) reuse both drive shafts, and either modify my current 208 T-case or find a 241c w/vss. With the 4l80 I'm not exactly clear as to what else I'm going to need to make it happen.

I'm assuming my 99 ECU will control the 4l80.
-do I need to purchase a trans of the same year, or will any 4l80 do?
-will my t-case options change?
-will drive shafts still work?
Basically, what are the differences between the 4l60 and 4l80 swap parts/install wise?

Here's a couple pics of my truck

Thanks in advance!!!

[Captain Swampy]

transmissioncenter.net has 5 levels for the 700r4. Level 3 will handle up to 600hp.

[throttle out]

Thanks for the link captain!
Lil pricey for me though lol

[Captkaos]

The 4L80E was first offered in 1991, that is the ONLY year transfer case that will bolt up and it was a NP205 and it would probably be easier and cheaper to find a gold brick.
You can run an adapter which is an option to bolt what you want to one.  Advanced Adapters is who I would call...
If the 99 ECU controlled an 80 it will or if it is a "411" ECU it can be flashed to control one.. 
There are 2 versions of the 80E, 91-96 and 96 up.  either can be made to work.
They 80E will make the drivetrain longer most of the time this depends on what you are bolting to it for a T-case.  The output shaft of the rear will have to change also.

[Irish_Alley]

its been a while since i did my research. but you can take a th400/208 adapter and make it fit the 4l80e, you can then use the 241 passenger side drop with a electric speed sensor for the ecm. the 4l80e needs a computer to shift or you get a "black box"($200) like i have but you have to manually shift it. i dont know if you could use the lm7 ecu to control the 4l80e and np241. i understand you can just repin a 4l60e ecm(round plug) to work with the 4l80e but i cant say this is 100% true. but the only difference in the 4l60e and 4l80e plug is two pins are crossed.

you will have to look at the pulse signal from the np241 and compair it to what t case came from a lm7. i dont know that one. also you can get a drivers side t-case (what would be on a 88-98 style) and then get a ford axle and run it that way

[throttle out]

Thanks for all the reply's fellas. Because of my budget constraints my turbo dream bubble is, for now at least, busted. I feel a 4L60E, for now at least, is going to be my best route. When the time comes 4-6 years down the road to turn this truck into a nasty animal, maybe the 6L80's will be more plentiful, and my bank account as well!! Found a nice project over at gmsquarebody.com and the guy disassembled his 208 and pressed a 40 tooth reluctor wheel to the output shaft of his np208. then bought a vss sensor, drilled and taped his case, and off he went.

[frotosride]

there is always the easier solution of the VSS cable adapter which will alow you to save $$ by retaining factory speedo. the only issue is if you plan to retain factory cruise control from the LM7. the pulse may be to low for the PCM to recognize for cruise control but plenty for the PCM to adjust fuel and spark tables due to being in drive.

Any progress?