Gen3 5.3 to BOP 2004r
Thread Starter
Teching In
Joined: Jun 2020
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Gen3 5.3 to BOP 2004r question!
will a BOP 2004r bolt up to a Gen3 5.3?
I pulled the big block Buick, left the trans (2004r) in the car, dropped the LS in and can only get the bottom bolt on each side in.
Cheers
1968 Skylark
will a BOP 2004r bolt up to a Gen3 5.3?
I pulled the big block Buick, left the trans (2004r) in the car, dropped the LS in and can only get the bottom bolt on each side in.
Cheers
1968 Skylark
No, as you discovered the pattern is different. You will need to buy an adapter or use a different transmission.
For GM V8 rear wheel drive transmission bellhousings I'm aware of three:
For GM V8 rear wheel drive transmission bellhousings I'm aware of three:
- GM corporate V8 bellhousing pattern - fits small and big blocks plus the 90° V6 (4.3, etc). Will work with LSx engines using proper spacer and flexplate. No upper bolt hole.
- GM LSx V8 bellhousing which is a modified corporate V8 with a hole on top and a missing hole on the upper passenger side - matches updated pattern of LSx engines and crank spacing plus bolts to the oil pan for additional NVH suppression.
- BOP bellhousing - fits the Buick, Olds, Pontiac and Cadillac engines. Identified by two widely spaced upper bolts.
Thread Starter
Teching In
Joined: Jun 2020
Posts: 10
Likes: 0
No, as you discovered the pattern is different. You will need to buy an adapter or use a different transmission.
For GM V8 rear wheel drive transmission bellhousings I'm aware of three:
For GM V8 rear wheel drive transmission bellhousings I'm aware of three:
- GM corporate V8 bellhousing pattern - fits small and big blocks plus the 90° V6 (4.3, etc). Will work with LSx engines using proper spacer and flexplate. No upper bolt hole.
- GM LSx V8 bellhousing which is a modified corporate V8 with a hole on top and a missing hole on the upper passenger side - matches updated pattern of LSx engines and crank spacing plus bolts to the oil pan for additional NVH suppression.
- BOP bellhousing - fits the Buick, Olds, Pontiac and Cadillac engines. Identified by two widely spaced upper bolts.
TECH Junkie
Joined: Jun 2008
Posts: 3,202
Likes: 1,390
From: Nitro Alley
No adapter is required, however a flat flex-plate and spacer will be needed to use a stock dimension 200-4R torque converter.
A custom converter is another option to mate the two.
TECH Regular
Joined: Oct 2011
Posts: 408
Likes: 4
huge torque , 4l80 prefered , after rereading your post I think you are probably dealing with a turbo 400 , thats the trany they came with [big blocks]
The 200-4R bellhousing was made two ways:
BOP only. Or BOP / Chevy dual pattern.
You could rebuild it into a dual pattern case.
You could run a bellhousing adapter plate (Chevy engine to BOP trans.)
The converter to crank will still need the spacer that's used for the TH350/TH400 converters. This was used on short crank trucks with 4L80.
BOP only. Or BOP / Chevy dual pattern.
You could rebuild it into a dual pattern case.
You could run a bellhousing adapter plate (Chevy engine to BOP trans.)
The converter to crank will still need the spacer that's used for the TH350/TH400 converters. This was used on short crank trucks with 4L80.
