4 speed to 8 speed conversion?

[Jake Kuhn 1,547]

Hey guys,

My b80 trans has been noisy ever since I got it, I was planning to rebuild it this summer. But after I ended up with this spare 8 speed I was thinking it might be a better and cheaper way to fix the noise, I won't have much into the 8 speed, maybe 75 bucks.

 

So my question is...what would I have to change to make it fit. Looking at it the only obvious difference I know I would need is the different shifter plate which I can get easily. What else needs modified or changed?

 

Thanks, Jake

[jimt1971 236]

Check the input pulley size it may need to changed. And the brake rod may need to be bent to fit.

[Kelly 1,028]

Only thing I can think of is the brake location, but with the right brake rod it should be a bolt in.

[Wheel Horse Kid 104]

We converted my 1045 from a 4 to 8 speed when we set it up for pulling (Probably would not have used it if I knew the 1045 was rare). Could not tell you all that was done as I was only 7 or so and grandpa did all the work, but I can tell you that it is a very fun conversion!   Good Luck!

[snookman1 1]

i have a 1974 b80 that  i swapped out the 4spd. for an 8spd. break rod was fine, in fact it was a direct swap on mine. should be the same for you. i have not done the shift plate because i can not find one, if you got one or the full size pattern that i could get let me know. i have a nice piece of stainless that i would like to transfer the pattern to.