Quick question.... is the C4 Auto trany interchangeable from year to year? like a 68 C4 would fit in a 66 C4's place? I ask this because I am going to buy a C4 trany from a junk yard and rebuild it then swap them out so that I have less down time with my car. Plus I don't like the "green dot" setup in my trany, I want the latter setup from the 67 on.... I believe that it is since the only difference I have found from them is the valve body that makes it a "green dot" trany or not. and it would make since because the 289 and 302 are identical in everything other then the cylinder length (bolt holes, size, weight, etc) so it would make since that the Trany side of the engine wouldn't change... any trany experts in the house?.... where is THUMPIN455?

 

Maybe its a dumb question but what is a "green dot" tranny?

 

Green dot transmissions have a different valve body setup then the normal transmissions in which that instead of having P, N, R, D, 2, and Lit has P, N, R, D, "green dot", and L. the difference comes in that when you have it in drive the "green dot" trany only uses 2nd and 3rd gear. However if you put the shifter on the green dot it will use all 3 gears.... then one more down to low and it only uses 1st gear.... Instead of the typical Drive using all 3 gears then one more down to "2" using 1st and 2nd, then going down to L and only using 1st. thus making it more difficult for me to manually control my tranny. and that in tails the reason I am swapping out to a normal tranny.
I hope this made seance to you.

Brian

 

It should swap just fine I believe.

 

bump, anyone else? imput, segestions?....
Should I rebuild the trany I have and just swap out the vavle body?

 

They will swap without a problem, but if it was mine, I would rebuild your tranny and have beefed up parts put in it. Not only would you have a rebuilt tranny, but you would have a beefed up C4 just in case you get a Cammer some day.

 

thanks for the explanation kbunny.

 

My pleasure, its fun to have the answer every once and a while.

 

Hey tranny guiy,
As noted previousley, have a shop install the latest pump, inputshaft, and clutch packs, while you're at it. By the way, the early C4s used a 5 bolt bell housing as opposed to the later use '65 went to 6 bolt. I put my OEM early 5 bolt on the shelf, purchased a '68 and had it modiied with the latest heavier upgrades. You can swap those bell housings around.
Good luck!

 

Ok, I have a 66 C4 that's in my car right now but its the way the valve body is setup that I don't like and ill be looking around but I might just have to live with it..... The way you talk it makes it sound as if I would be having a shop do the work?.... No way man, I have some experienced help as well as my own limited experience so I wont be spending the 399999 dollars it costs to have someone else rebuild the trany for me. plus Ive been told C4's are one of the most easy automatics to rebuild.