wat 208 works?

[Jjay78]

i think even the 205 needs a longer shaft than the 203, but not 100% on that one

[7387chevynut]

Since this is getting serious I better get my 2 cents in on this............Ohearn...check out my drivetrain pages under the (politics board....top of that page)..........it'll tell you all you want to know about 205s, 203s and 208's..............


To answer your question (your last question to start with).......any 1970-1980 model NP205 that was behind a 350 turbo trans will bolt right up to your current 350 trans.


Now to start off with the very beggining of your questions.......All 1970-1980 4x4 350 trannys had SHORT tail shafts..........ever notice that THIN 203 adaptor plate???.................205's used a splined coupler inside its adaptor to join the trans shaft to the 205 shaft.

IN 1980 for the (1981 ) model year GM began using the NP208 but its current 1/2 ton auto trans was still the 350 turbo, so they lengthend the rear output shaft on it to work with the NP208. So from Mid 1980 till Mid 1981..........GM offered the 350 turbo with the NP208................making it a very rare trans/t-case combo to find.

For the 1982 model year, the 350 turbo was done away with in GM's 4x4 line up. The (New for 82) 700R4 replaced it, which is why 700R4's are sooo much easier to find.

Gearing wise, the 205  lacks good low range, its only 1.96...........compared to the NP203 which as 2.01 low range.................compared to the NP208 which has 2.62 low range.

The 205 is stronger strength wise becauses its all Gear driven inside and has a cast iron housing. While the Np208 is chain driven with an aluminum housing, but dont let that fool you, the 208 is strong, and many members on here will attest to that fact.

What will be easier for you to do?  If you wanna get your rig on the road quickly.......then get a 205 from a 350 turbo.  If you want that Np208..........thats gonna be more time consuming, and will result in either swapping out your current trans for a differrent 350 trans that will work, or pulling out your trans to modify it with a longer shaft. Or swapping in a 700R4.

Basically if you dont want to swap out your perfectly good trans, then your options are limited to either keeping the NP203, or getting an Np205.

[OHEARN.2012]

thanks for the info guys i guess ill be waiting to do this swap till winter any1 able to lengthen that shaft?

[betterbeaters]

i think even the 205 needs a longer shaft than the 203, but not 100% on that one

205 and 203 use the same trans out put shafts

[OHEARN.2012]

i just hate this 203 cant get it in 4 lo lock i want 2wd so i can see how badass my truck is

[7387chevynut]

i just hate this 203 cant get it in 4 lo lock i want 2wd so i can see how badass my truck is

If its not going into LOW LOC..........then it might be a external linkage issue.

And for wanting 2wd.............run LOCKOUTS on it..........but you will have to run the T-case in HI LOC.........for 2wd.................BUT if you try keeping the lever in the ( HI ) postition with the  hubs unlocked...........the truck will not move while in gear, it'll act likes its in neutral......thats because the T-case senses theres no power going to the front axle.

[OHEARN.2012]

yea the font dshaft will sit and spin and no movement i just want some better low speed gearing and using the 208 will help with that

[Jjay78]

i know the feeling, been running a 203 in my truck for years, only thing i do like about it is the extra 2 low the case offers