Chev bolt pattern 904?

Ken Parkman · 05-31-2025, 08:41 PM

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.

jmantle · 06-06-2025, 04:53 PM

Quote:

Originally Posted by Ken Parkman

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.

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).

devo340 · 06-06-2025, 04:56 PM

Postal Jeeps is what I heard they came from.

Mark Yacavone · 06-06-2025, 09:19 PM

Quote:

Originally Posted by devo340

Postal Jeeps is what I heard they came from.

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.

Ken Parkman · 06-06-2025, 11:06 PM

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.

Mark Yacavone · 06-07-2025, 12:11 AM

Quote:

Originally Posted by Ken Parkman

They were actually quite common in cars. Came in AMC cars with the 4 cylinder from 78 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.

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 ;-)

05-31-2025, 08:41 PM	#1
Ken Parkman Junior Member Join Date: Apr 2024 Posts: 7 Likes: 1 Liked 4 Times in 3 Posts	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.

06-06-2025, 04:56 PM	#3
devo340 Junior Member Join Date: Apr 2016 Location: Sapulpa, OK Posts: 92 Likes: 124 Liked 168 Times in 30 Posts	Re: Chev bolt pattern 904? Postal Jeeps is what I heard they came from.

06-06-2025, 11:06 PM	#5
Ken Parkman Junior Member Join Date: Apr 2024 Posts: 7 Likes: 1 Liked 4 Times in 3 Posts	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. Last edited by Ken Parkman; 06-09-2025 at 11:05 PM.