mcutlass1969

ok i have a 1969 cutlass S. I pulled the 350 out and I am putting in a 455. The 455 has a Large F on the side of the block and a 396021fa on the front top on the block. Here is the issue. The 455 motor mounts will bolt up the block but cannot slide over the Journals on the Frame. The old 350 motor mounts appear to might work but the local part store can't match them to their stock. What are my options? the block was from a 76 Toronado from what the junk yard told me.

Mike

Oldsguy

Try this link, hope it helps you out.
http://www.realoldspower.com/phpBB2/...ghlight=mounts

mcutlass1969

Thanks

Dave H

Olds used the same frame pads on all Cutlass 442 for both small and big blocks up through 1968. The 65-68 442 and Vista Cruiser (400cu in) used a different rubber mount with an inner reinforcing design much like the later big block mounts. Dimensionally they were the same as the small block mounts. Those 65-68 mounts have been unavailable for years and parts places subbed in the regular 350 mounts.
In 1969, they redesigned the frame pads for the big blocks and incorporated a sleeve inside to strengthen it. GM had a huge problem on this on Chevies, and actually had to recall cars and put a strap on them to keep the engine from dropping down if a mount broke. This was a huge safety problem on the 64-67 cars that had a fixed throttle linkage instead of the later cable design. When the engine dropped, the throttle opened wide open. OOPS.
By the time they got around to fixing it, it was almost moot since all cars went to a cable throttle control in 1968, but GM management put out an edict to redesign the motor mounts on all cars to the reinforced pad design whether you needed to or not. First efforts of centralized corporate design control by Central Office.
Adding the sleeve inside the frame pads necessitated a higher pad and subsequently moving the pivot bolt location away from the frame. Olds then had to redesign the rubber mounts to accommodate this to be compatible. It was only on Big Blocks at that time. Small blocks continued to use the previous design without the sleeve.
Best to keep the mounts matched in sets and not mix them (especially when changing from a small block to a big block (just use the small block mounts and all is fine). Kinda messy though as there's such confusion into what you're buying from the parts stores and the repro guys. Match your old parts and you'll be OK.

Cornfusing? You betcha. And a sign of things to come as GM started wielding their big corporate club and telling the Divisions how to do their jobs.

mcutlass1969

Dave
Thanks for the advice. So what your saying is that I can use the same style of motor mounts that the 350 used. It appears the bolt holes would line up on the 455. Now here is another question. I also have another 455 out of a 72 olds 88. After looking at those motor mounts there were large slugs like washers on the passenger side of the block. Do you think I will need this for the Custless or were these due to the motor coiming from a larger car?

Dave H

Not familiar with those washer/slugs, but all Olds V8 engines in this era have the identical bolt patterns on the block. You don't need them on your application. Just install your Big block with either the original mounts and bolts or replace the mounts with new ones for a 350.

In general the only difference between a big block Olds and a small block Olds is that big blocks have about 1 inch more deck height (for the bigger stroke) and the cylinder heads are moved outboard and upward. Everything is the same dimensional (externally) from the timing cover down.

mcutlass1969

Thanks Dave

Mike