Hey I'm hoping someone here can help. I have a 72 Lemans came with a 350 that had some serious issues with it. I went to replace it with a 400 out of a 77 Grand Prix. I can't find motor mounts anywhere that will fit the pre-tapped frame. The mounts I found are too long. This is my first resto so I'm looking for some added help. Thanks in advance!!
motor probleme
- Thread starter fency2000
- Start date
cammerjeff
Well-known member
You are going to need some Adapter Plates, While it is true that all 65-79 Pontiac Blocks are very much the same, the big differences are the motor mount Holes. Early 65-69 blocks only have 2 motor mount holes drilled and tapped and are either made for A (lemans/Tempest/GTO & 69 Grand Prix) and B body (Catalina/Bonneville/65-68 Grand Prix/Executive) cars, or F body (Firebird) but can be interchanged with adapter plates.
The 1970 - Early 1976 engine blocks have 5 motor mount holes drilled and tapped, and can be used with any year and Model Motor mounts. Late 76 and 77-79 engine Blocks were made with only the Firebird style motor mount holes, and the other cars Chassis were made to fit those style mounts.
Butler Performance has a good chart showing the differences, and have various adapter plates and kits available
http://www.butlerperformance.com/products/fasteners/motorMounts.htm
It looks like you would need the Kit #WRP-MM2 that they sell for $149.95
But you may be able to find it cheaper at another Pontiac supplier such as AMES, Performance Years, or Possibly NPD if you shop around.
Good Luck, hope this helps.
The 1970 - Early 1976 engine blocks have 5 motor mount holes drilled and tapped, and can be used with any year and Model Motor mounts. Late 76 and 77-79 engine Blocks were made with only the Firebird style motor mount holes, and the other cars Chassis were made to fit those style mounts.
Butler Performance has a good chart showing the differences, and have various adapter plates and kits available
http://www.butlerperformance.com/products/fasteners/motorMounts.htm
It looks like you would need the Kit #WRP-MM2 that they sell for $149.95
But you may be able to find it cheaper at another Pontiac supplier such as AMES, Performance Years, or Possibly NPD if you shop around.
Good Luck, hope this helps.
