465/208 to 205 swap questions

[rustwagon]

Just fell onto a 465/208 combo, and would like to know if a 205 or better yet a 203 would be a direct bolt on. I searched around and couldn't find a solid
answer.

[phoenix]

I have a SM465 trans with a 205 on it in my garage. I know there are two bolt patterns for these. There is a round pattern and an elongated pattern. mine has the elongated pattern.

[ryanroo]

the only one that will fit on that 465 is the round pattern 205. they are a little harder to find as the only came in 85 and newer 1 ton chevys.

there is no 203 that came stock with that set up. if you got a 203 from a th400 truck you could drill the 203 case for the round six bolt pattern and make it work i think. that is how they are made to work for the nv4500 in a doubler set up
Ryan

[rustwagon]

the only one that will fit on that 465 is the round pattern 205. they are a little harder to find as the only came in 85 and newer 1 ton chevys.

there is no 203 that came stock with that set up. if you got a 203 from a th400 truck you could drill the 203 case for the round six bolt pattern and make it work i think. that is how they are made to work for the nv4500 in a doubler set up
Ryan

For a doubler was the only reason I was thinking about the 203. Guess i'll start running the pull lots here in denver to see if I can score the 205 before we move. Probably more selection here. Just wouldn't feel comfortable hammering on a 208

[Swampthang]

IIRC, the round pattern 205 also has 31 spline input. Your SM465 is probably 10 spline.

[ryanroo]

IIRC, the round pattern 205 also has 31 spline input. Your SM465 is probably 10 spline.

the round pattern is a female 32 spline input and the 465s that came in front of them had a longer than normal 32 spline male output

ryan

[kwai]

Just for clarification, Ryan is talking about the specific 465 that is mated to the 208. Most 465's had a 10 spline output and can be found mated to either a 205 (common) or a 203 (less common).

[ryanroo]

Just for clarification, Ryan is talking about the specific 465 that is mated to the 208. Most 465's had a 10 spline output and can be found mated to either a 205 (common) or a 203 (less common).

this is basically what it is. the 465s that where mated to the 208 have the long 32 spline output. after the mid eighties (roughly 85) all of the 465s where this way. even the 465s mated to 205s (only available in the 1 ton) had this long 32 spline output. the earlier 465s from the late 60s ish till the early-mid eighties had a 10 spline short output. these where mated to either 205s or 203s, but the 203s were less common. i believe in 74 unless the truck was ordered specifically with part time 4x4, meaning 205, they where equipped with the 203. after 74 it was not standard issue, but it was an option for the full time 4x4 that means the 203. this applied to 4 speed trucks only. so, if the 465 has a 208 behind it, i was a truck made after 1980, and if you want to swap a 205 in, you have to find the more rare 205 from post 1985 that was behind a 465 or a th400. the 205 will bolt to the 465 with the long 32 spline output without issue.

so in short, after 1980 the 4 speeds with 208s came in half and 3/4 tons. these trucks did not have the 205

during part of 85 and after, all of the 465s, including the 1 ton trucks where the long 32 spline output. only the 1 tons have the 205 and it had the round six bolt pattern instead of the oblong 8 bolt pattern

from 69 or 70 untill 1981 the 465s with either 203s or 205s in half and 3/4 ton trucks had a 10 spline short output. the one ton trucks after 1980 had the same old short 10 spline output untill 1985 sometime.

in 1980 all 4x4 GM trucks came with 205s.

starting in 1981, only the 1 tons had 205s

ryan

[rustwagon]

thanks for the good input. I'm moving the truck up to the shop next week to get the rocks under it and the engine stuff swapped out. Has to be up and running by June 1. On the afternoon of June 1 it has to start a 1000 mile move under its own power. Once I get it to the other end, i'll use it through the summer to run a few light trails and move stuff around the farm while the shop is being built. Next winter i'm ripping the whole thing completely apart and starting from the frame up.

Now to make a walk through the pick-a-part yards in denver tomorrow so I can see if I can spot a newer 205.

[ryanroo]

i have a spare if you are interested. ill post up some pics later and some info

Ryan