203 to 205

[77chevyshortbox]

I was wondering how hard it would be to take a 203 transfer case out, and replace with a 205. would it be as easy and just unbolting the 203, and bolting the 205 in? or do i need to change anything around.

thanks.

[Prong]

Spline counts are different unless you find a 27 spline from the pre 73 T350 tranny equipped trucks (assuming you have a T350 tranny now).

[77chevyshortbox]

yeah ive got a th350, its a 77'. so what exactly do i need to know or do to switch over?

[Irish_Alley]

the 205 if off a th350 then it will slide in with 27 splines but if it came off another transmission it will have different spline count causing it not to slide in aslo due to shaft length differents. now the rear shaft I can't help you with but in 77 the 302 came with and changed to the 32 spline front output shaft from the post 77 that had 10. so best thing to do is remove your drive shaft "rear" and count the splines, count the front now the front I can tell you if the front shaft bolts to a yoke by the u joint than it will have 10 splines. if it bolts up to the flange by a flange than it will have 30 splines

[77chevyshortbox]

so if i can find a 205 off of a th350 then i should be set?

[Irish_Alley]

you have to count the splines cause in and around 77 is when they changed splines for the front  if you look at the front drive shaft if it looks like a yoke its pre 77 if it hase a square flange then it post 77 you have to have one with the same inless  you find a 205 with the front drive shaft for the front. the rear should be the same but it might have a slipe yoke for the new style or a yoke on the shaft for the old style

[77chevyshortbox]

alrite thanks. well once i drop the tcase ill find out i just wasnt to sure. i wanna get rid of my 203 i really dont want a fulltime truck. and i decided to just get a 205 but i wanted to know how hard it would be and what i needed to know. so thanks alot for all your help with all my questions. im sure if i need to know anything else i can count on you guys as always lol. but again thanks.

[fitz]

Keep in mind if it turns into a hassle theres nothing wrong with a 203 with a part time kit installed in it.

[Irish_Alley]

my 203 is part time and its holding up to  my abuse. broke a couple axles drive shaft but the 203 is still sticking around. the olny thing I don't like is the yoke on the pre 77 that I have I want a flange like the post 77.

[77chevyshortbox]

i got a question. if i have the drive shafts that match the transfer case, can i install them onto my diffs? or will it make a difference.

[77chevyshortbox]

so i went and looked at the truck i was going to take my parts off of. it has a th400 in it, and my truck has a th350. from what i know the transfer case isn't compatabile is it? anyways, can i strapt this 205 onto my th350 or do i need to take the tranny to.( i was debating on taking the 400 anyways, herd their alot better tranny's) but yeah sorry for the dumb questions im not sure on all this stuff, still learning.

[smitty77]

If the TH400 tranny is good I would take that as well and it makes the whole swap easier, IMO.  And maybe the driveshafts off of the donor vehicle if they are available.  Take what you can so that you're not held up as you scrounge for some oddball part, and then sell the extra parts once the swap is done.  You could conceivably get out of this swap for even-money if you get a deal on the parts and sell your TH350/203 for a good price.

Reportedly the TH400 is a stronger tranny.

[Irish_Alley]

i got a question. if i have the drive shafts that match the transfer case, can i install them onto my diffs? or will it make a difference.

yes they can be swapped out even if it has a diffrent u joint (ex. you have a dana 44 front diff and the donor truck has a dana 60) then you would have to go to a parts store and tell them what you have and they will get the right u joint for ya.

so i went and looked at the truck i was going to take my parts off of. it has a th400 in it, and my truck has a th350. from what i know the transfer case isn't compatabile is it? anyways, can i strapt this 205 onto my th350 or do i need to take the tranny to.( i was debating on taking the 400 anyways, herd their alot better tranny's) but yeah sorry for the dumb questions im not sure on all this stuff, still learning.

the th350 has a 27 spline count on the output shaft and the th400 has a 32 spline count so no they cant be swapped the th400 tho is a tranny that is found in most 3/4 and 1 tons while the th350 is only i think found in 1/2 tons so i would just swap the whole thing out. if lets say the 400 came out of a long bed (longer drive shaft) and the 350 came out of short bed then you could just pop the u joints out of the yokes and swap them around they should fit with the right u joints

[Irish_Alley]

but i did have a th350 w/ np 205, gave it to my buddy its in his blazer now lol. he burnt up the rev i don't think she like the 44's much. just letting you know they do make a 205 for the th350

[77chevyshortbox]

see the np205 is free. as well as the drive shafts for it. the tranny i might have to pa for. but no more than 100 bucks. so yeah i'll probably just take it all. thanks. i wasnt sure about any of this lol. now i know