I went through this when I swapped mine. the specific frame pads you're looking for are very hard to find, as there weren't a whole lot off 455 73-74 Buick A-bodies made. And even fewer in wrecking yard. I made a set from the easy to find big-car frame pads. They're taller than you need, so cut the flange off, mock them up til you like the position, and weld a piece of plate to the bottom. Drill your holes and shape to your liking. Maybe this method isn't for everyone, but when done correctly, it works perfect and looks almost OEM.
Ken, I think I have them. I'll get you some pictures. They are steel, similar to 350 pads but wider and taller and fit 455 engine mounts. I'll give them to you if they are what you need.
These are what I have. They were attached to a 71 455 that I believe came out of a b body buick that the p.o. had "hack"welded into a 70 gs chassis.
those look about right. certainly Id like to test fit them. If nothing else they would be a good start on a custom made set.
this has been a discussion before,those pads in the picture are from a big buick,they wont work the way they are they are 3/8 too high,im in the process of doing another car right now,take the mount and lower them exactly 3/8 of a inch and they will fit perfectly bolted right to the frame where there suppose to be.
Thanks again for the assist. Bigpig455 Measured frame pads on his car and the bolt stood 1" off the cradle. I measured these frame pads at 1.375" This confirms what you said exactly. I will make my own flanges and cut 3/8 off these mounts, then weld it together. Onward.....
These part numbers were 1236486 and 1236487 I cut 3/8 off and welded them back. Preliminary measurements show the right 1" bolt height now. When they cool I will test fit and take some pics.