[tekuhn]

I'm curious if anyone is familiar enough with the two different mount designs to comment on whether one is stronger than the other? There must be some reason why they chose to give the 455 a different mount when the 400 mount would bolt to the engine fine.

For my custom project, I'm using a dual pattern 5-bolt block, so I can use either mount and might use the 455 mount if it's indeed stronger.


Thanks in advance for any information!

[thepontiacman]

If your car has the regular mounts on frame, that is what I have always used for 455.
I had no problems with the 400 mounts running a 455. Ran them for years.

The 455 mounts were wider and maybe stronger but I wouldn't spend time changing them.

Sent from my Moto Z3 Play using Tapatalk

[tekuhn]

This is a new installation to a fabricated crossmember and I can use either mount as a starting point. My block accepts either bolt pattern, so just curious if one has an advantage over the other. I too have used 400 mounts on a 455 with no issues.