shift pattern is: (ignore the little``` things)
R````1`````3
|____|_____|
`````|`````|
`````2`````4 (overdrive)
I have had excellent luck with my 89mm. I run a bored out 261 with a 9" Ford with 3:50 gears. 2000 rpm is 65-67 mph in overdrive. First gear is a little fast for a parade gear--if I would slow my engine idle down it would be perfect.
BE CAREFUL which version you get. The MOPAR version A833 will have a fine splined input shaft with a much larger pilot bearing stub that the GM. I believe the GM is something like 10 splines and a 1/2" pilot bearing stub while the MOPAR is 21 splines and a 7/8" pilot bearing stub. The mopar input shaft is at least one inch longer than the GM input shaft. Also the transmission will not bolt up to a GM bell housing. A fellow 'Bolter (Ken) and I had figured out how to make an adapter plate to mate the MOPAR tranny to a GM bell housing but I ended up finding a GM version so now the MOPAR tranny I bought will either be sold or used as an internal parts source for my GM 89mm.
The input bearing housing on the 89mm will need to be machined (O.D. reduced) to fit a bell housing that previously used a Muncie SM420 or other vintage tranny. The more modern bell housing for the Muncie SM465 has the correct diameter. I took the bell housing I wanted to use and the input bearing housing to my machinist and told him I wanted to fit this bell housing to this input housing. He bored some material out of the bell housing bore and turned the input housing to match and it worked great.
Last edited by Racecarl; 10/08/2008 4:11 AM. Reason: had to look at previous post
