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Old 09-09-2018, 03:23 PM   #1
RDrancher
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4L80e to NP208 Need Answers

I'm picking up an LQ4 with a trans tomorrow and have the choice for either a 2WD or 4WD 4L80e. I've been searching and can't find a straight answer as to what is involved in adapting either trans to my '88 NP208.

Which trans should I get for the easiest and most economical swap?

It sounds like I'll need a 32 spline output shaft and an electrical speedo, but what else? I need a list...I love lists

If it's too much of a hassle ($) I will just rebuild my present 700r4.
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Old 09-09-2018, 04:19 PM   #2
sweetk30
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Re: 4L80e to NP208 Need Answers

4l80-e = 32 spline rear output .

t-case needs to be from th400 / 4l80-e / later stickshift there all 32 spline input gear . or you could swap the input gear .

208 did not come electric speedo . you need a 241 for that up to 1991 last year suburban / blazer . crew cab go the 205 .

241 is a little better t-case over a 208 tho .

as to the 4l80-e the round pattern to t-case basicly stayed the same maybe they clocked a hole differant from pass side to driver side drop t-cases i am not 100% on that to be sure .

if 2wd will have a tail shaft to long for most t-case bolt on needs and will not be able to have full spline fit if you cut it shorter . so best bet start with 4wd case 4l80-e to get you the closest to your needs .

4l80-e is little longer than the 700r4 . also it has no deep first gear like a 700r4 does . its the same gear ratio's as a th400 but lockup and o.d gear is all .

hope this helps .

oh ya and make sure what ever combo you get the flywheel pattern fits the 4l80-e convertor pattern . guys have found this out and had to pull engine or trans and swap it . . . .

and this guy is just down the road from you . greg is GREAT guy and helps lots of guys on my other forum i hang out on with parts / info / even whole transmissions shipped . http://www.phoenixtrans.com/
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Old 09-09-2018, 04:32 PM   #3
RDrancher
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Re: 4L80e to NP208 Need Answers

Awesome and thanks you! I'll get the 4wd trans. This will be a learning experience, but I can't imagine the cost of adapting the 4L80 being more than a bulletproof 700r4.

I believe I also read somewhere that there's an adapter needed, but that the adapter allows clocking the 208 for better front driveshaft clearance. I'll see if I can find that. And yes, the 241 is probably stronger, but I'm pretty sure that that would put the drop on the wrong side for my front diff.

Also read that I could use the speedo in my cluster from a 89-91 Suburban or Crew Cab.
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Old 09-09-2018, 05:23 PM   #4
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Re: 4L80e to NP208 Need Answers

241 can be had in pass side drop for last 3 years of solid axle square body trucks / blazers / suburbans .

and 90-91 for electric speedo .
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