Chev bolt pattern 904?
 

Is the 904 with a Chevy bolt pattern legal in Super Stock? Being an AMC guy where they came from I just picked one up with some other 904 stuff. Don't really have a use for it but was curious if it was legal.

Re: Chev bolt pattern 904?
 

From the rule book,
Any model transmission, same make as car, with a maximum
of three forward speeds (unless OEM equipped with more
than three forward speeds).

Re: Chev bolt pattern 904?
 

Postal Jeeps is what I heard they came from.

Re: Chev bolt pattern 904?
 

They did... along with the 153 Chevy II 4 cylinder.
I guess the PG wouldn't cut it , especially around Christmas time ;-)
The question would be..Is it a truck transmission (Jeep) or car.?
Nobody is going to fight this one out today anyway.
A Pro-trans is essentially 904 style aluminum pieces in a T 350 case.
Brake , multiple gear ratios etc.
Anybody that can afford a SS car can afford the Pro trans too
They were used in Comp for a while but anything goes on the trans there, depending on class.

Re: Chev bolt pattern 904?
 

They were actually quite common in cars. Came in AMC cars with the 4 cylinder from 80 thru the end of car production in 83. Also came in 4 cylinder jeeps from 81-83. They made quite a few, but that stuff is all rotted apart now. Dunno why I picked it up; probably just a conversation piece.

Re: Chev bolt pattern 904?
 

Okay, I was lead to believe the 904/ Chevy pattern was first used with the 153 Chevy engine .I can find no evidence of it, though. The Chevy pattern was used on the early Iron Dukes. It was continued when AMC used that engine. Non lockups with the 4 cylinder cars and Jeeps. So yes it was a "car" transmission.
Not being well versed in the foreign cars, that one slipped by me ;-)

Re: Chev bolt pattern 904?
 

Having worked for a AMC/JEEP dealership for 40 years and during 79-83, we saw very few AMC cars sold with the Iron Duke engine and an automatic trans.. Base model CJ5 Jeeps with the Iron Duke with an automatic also were few and far compared to stick shift BW SR4 transmissions.
The AM General DJ5 Postal Jeeps to my knowledge from 80-83 were all Iron Dukes with 904's behind them . I never saw one with a manual trans

Re: Chev bolt pattern 904?
 

The mail trucks used to come with a 153 4 cyl, and a THM 180, which is a 3 spd made in Europe, mostly for Opel. When that trans was discontinued, that is when the 904 with the Chevy bell was created. The 180 was replaced with an overdrive added on, basically a 200-4R overdrive gearset was added between the converter and the 180. That is the trans that GM sold to BMW, and the OD ratio was slightly reduced to .72 ish.