ok so im wanting to swap my boat anchor 203 out for a better geared 208 and i didnt know wat i was looking for. i know im looking for a 208 and my trans is a 350th. i know that a 208 off of a 400th wouldnt work and idk with a manual??? wat about a 700r4 would that one work?? need to know so i know wat to look for and wat spline count shud the shafts be?
thanks kyle
the stick shifts and the 400's both use the bigger input, you need one off either a th350 or 700r4
are they easy to find?
yeah
ok so any 208 off a 700r4 or 350th will work no mater wat?
they should, their all pass drop just make sure your get the adapter plate you need
oh the output shaft on your 350 is gonna probly be to short for the 208
81-87 4spds, and th400s have a 32 spline output. 350, and 700, are 27 spline.
correct me if im wrong but
you could find a long tail th350 and cut 1 1/4in? off it and it should work. i think some ppl have donr that on this site...
I got a mediun shaft (short shaft 2wd) 350th cut about a inch out of it and with the 2" spacer it works great!
Quote from: Le Dude on July 01, 2011, 12:21:02 PM
81-87 4spds, and th400s have a 32 spline output. 350, and 700, are 27 spline.
correct me if im wrong but
you could find a long tail th350 and cut 1 1/4in? off it and it should work. i think some ppl have donr that on this site...
depends on the tranny and the adaptor plates, i've seen from just over an inch to just shy of an inch and a 1/2
i have done it but its hard to cut sawzall wont even scratch it and it will take abought 5 cut off wheels lol
so will a 208 bolt right uo or will i have to cut and weld on a new piece?? wondering if i can make do this in a day or shud it be a project for the winter
your gonna wana find a different trans with a longer output shaft and use that one, and to cut off the shaft takes about 10 min
well wat about a 205 idk i dont want to waste this trans it works great??
i know a 208 has better gearing would a 205 be good too?
205 has worse gearing than a 203, but it's a lot stronger
it confuses me somewat so ur saying even a 208 that come off of a 350th wouldnt work?
you asked about different transfer cases, the 208 has the best gearing out of the 3 you were talking about, and the 205 is the strongest
yea i get that but didnt they put 208s behind 350ths??
yeah they did, the out put shaft on a 350 needs to be longer than the one for a 203
ok wat about for a 205 could i put one on my 350th without any mods and run it so i can 2 wheel it?
i think even the 205 needs a longer shaft than the 203, but not 100% on that one
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.
thanks for the info guys i guess ill be waiting to do this swap till winter any1 able to lengthen that shaft?
Quote from: Jjay78 on July 02, 2011, 11:41:44 PM
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
i just hate this 203 cant get it in 4 lo lock i want 2wd so i can see how badass my truck is
Quote from: OHEARN.2012 on July 03, 2011, 01:19:07 PM
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.
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
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