which frame mount holes do I use for olds

[84dragcutlass]

Its been so long since I've taken this thing apart, which frame holes do I use for the mounts for my 455?

 

[pontiacgp]

I think FE3X_CLONE put a BBO 455 in his car...he might be able to help you

 

[Bonnewagon]

If any line up, use those, but I have always needed to add new holes. I set a short block/transmission in place and judge from there. You can either tack weld the mounts in place or spray paint the outline. Then remove the block and secure the mounts properly. I find it beneficial to cut small access holes in the front of the frame so a long handled box end wrench can get the nuts in there no sweat. Luckily this bitchy job only needs to be done once.

 

[84dragcutlass]

Well I know the mounts for the 455 are the same and in the same spot as the old 307 mounts were so I shouldn't have to drill holes but I'd hate to bolt the mounts in and then find later I put them in the wrong spot. I have all the suspension off so not hard to get to at the moment.

 

[84dragcutlass]

Also will the factory 455 dual exhaust manifolds fit in a body?

 

[Bonnewagon]

"the mounts for the 455 are the same and in the same spot as the old 307 "- that makes life easy. I was always crossing division lines. So then all you need to do is lay it in there and check with a carpenter's level for proper fit. I'm sure the correct holes will reveal themselves.

 

[FE3X CLONE]

These are the two you need:



Better yet, the diagram from the Chassis Service Manual:

 

[84dragcutlass]

Thanks FE3X they sat back farther than i was thinking. Hoping to get the frame finished painting and get the mounts on this weekend so i can get ready to drop the 455 in

 

[Fox80]

These are both sides on my car before the frame was painted, it's for the 260 but should be the same

 

[olds307 and 403]

The 455 manifolds are supposed to fit a 455 without issue in a G body. Unfortunately, they lose something like 75 HP compared to the ARH high quality and dollars headers.