65 motor mounts

Supercars Unlimited shows 2 different numbers for the mounts that attach to the engine. I think the ones that are on the frame are the same but I'm not 100% on that one. I'm sure Ram-Z or Bro can speak up for this one.

Now I am really beating my head against the wall.. clear as mud.

just having some bad days, and thought I would relax and work on the 65, but I am not relaxing.

Motor Mounts & Mounting Pad Selections:



The question of which motor mounts to use when replacing an A-Body (F-85, Cutlass, Cutlass S, Cutlass Supreme, 442) small block with a big block is one that's asked all the time.



All Olds engines (big and small block) have the motor mount bosses in the same location in relation to the crank centerline. The only difference is the deck height. The year of the block (or the displacement for that matter) has absolutely NO effect on the type of motor mount to use. The only thing that matters is the matching frame mount. You must use the motor mount that matches the frame mount in the car.



If it was orignally a small block car and you do not intend to change the frame mounts, get small block motor mounts. These will bolt to the big block and will allow the engine to sit in the exact same location relative to the frame as it would have in a factory installation. Alternatively you could use matching big block motor and frame mounts, but for all this extra expense and effort the engine will still be sitting in the same location.



Small block engine mounts with small block frame mounts - OK

Big block engine mounts with big block frame mounts - OK

Small block engine mounts with big block frame mounts - the engine will be 1-2" too low

Big block engine mounts with small block frame mounts - the engine will be 1-2" too high



Note: The big block is about an inch taller than the small block when measuring from the crank centerline to the carb flange, so even if you use matching mounts, the air cleaner and valve covers will be higher in the engine compartment. The crank centerline, fan, and flywheel will all be in the same location as they were with the small block.



"The only thing you need to remember is that the rubber motor mounts and the metal frame mounts need to match. Nothing else matters."



The 64-69 small block and 65-68 big block motor mounts are identical. The 1969 400 mounts (and 455 for the 69 H/O) were changed to the taller design used on the 69-72 cars. The small block mounts were changed in 1970. Sealed Power 270-2261 - 1964-69 all V8 exc. 69 w/400



History

1964 - 1968 small and big block motor mounts 270-2261

1969 - 1972 small block motor mounts 270-2261

1969 - 1972 big block motor mounts 270-2328

1973 - up small and big block motor mounts 270-2380



The problem started in 1969. The original motor mounts used on the earlier cars were simply two pieces of metal with rubber molded in between - there was no interlocking feature. GM went through a massive recall in the 60s to repair broken motor mounts of this design. As a result, the big block cars, starting in 1969, got the interlocking design. Unfortunately, this design required the motor mount to be taller, so the frame mount was changed to move the cross bolt (the bolt that attaches the motor mount to the frame mount) further down on the frame mount. The 64-68 (and 69 small block) frame mounts have the cross bolt hole about 1 1/2" down from the centerline of the two top bolts that attach the frame mount to the crossmember. On the 69-72 big block mounts, this dimension is about 2 1/4". The rubber motor mounts are correspondingly different (the 69-72 big block motor mount is about 1" taller than the 64-68 V8 (and 69 small block) mounts.



In 1970, Olds redesigned the small block mounts to also incorporate the interlocking feature, but did this in a way that did not require the cross bolt to be moved. Thus the 70-72 small block frame mounts still use the 1 1/2" dimension. There is, however, a difference between the 70-72 small block mounts and the 64-68 V8 (and 69 small block) frame mounts. The raised pad is smaller and biased towards the top of the mount. Thus, I do not think it is possible to use the 70-72 small block motor mounts on the 64-68 frame pads. On the other hand, it probably _is_ possible to use the 68-68 V8 (and 69 small block) mounts on the 70-72 frame mounts.



Finally, starting in 73 Olds realized that there was no reason to maintain two different motor mount designs and went back to using a common motor and frame mount design on both big and small blocks.



And one more word of advice. Don't rely on any catalog, other than the factory parts catalog, to tell you what motor mounts fit where. As I noted in a prior post, the Sealed Power catalog is flat wrong.



Identifying Frame Pads:

You can check by measuring from the center of the two top bolts that hold the mount to the frame to the center of the cross bolt that attaches the frame mount to the motor mount. The big block frame mounts will measure about 2 1/4", while small block mounts will measure about 1 1/2". Whichever ones you have (big or small block), get the motor mounts to match.



When bolting the motor mounts to the block, there are three tapped holes on each side. The front two are for full size cars, the back two for F-85's.



The 1970-earlier B/C body cars use a motor mount that is completely different from the A-body mounts. The rubber mount has a threaded stud that fits into a hole in the frame. A nut is installed from the underside. One other wrinkle is that some B/C body cars DO use a 1" shim under one motor mount (see notes on the Cutlass offset engine myth.) If the shim is there on the 350, use it in the same place on the 455. Also, note that B/C body motor mounts bolt to the forward two of the three bosses on each side of the block. The A-body cars use the rear two bosses.



Q) Are the 69 onward small block motor and frame mounts exactly the same as the early "one size fits all V8's" units.



A) The answer unfortunately is no. The 69-up small block mounts are not the same as the 68-down universal mounts. The net combination of matched motor and frame mounts for a specific year is always the same, but the individual parts may be different from year-to-year.



Q) What is the earliest year motor and frame mounts that will put a V8 into an A-Body?



A) 1964 330 motor and frame mounts used as a matched set will install any 64-up (except, of course, the 394) Olds V8 in a 64 A-body. Ditto for 65, 66, etc.



Q) Are there any better quality mounts or mounts to avoid?



A) General concensus is that the G.M. rubber mounts (made in the U.S.A.) are the best rubber ones. Also, for reference, the Mondello SM300 mounts appear to be solid versions of the Sealed Power 270-2261 mounts and SM400's appear to be the solid version of the 270-2328.

so does anyone have an idea who to buy sealed power 270-2261 mounts from? fusick? supercars unlimited? etc.

what was the part number? they only show the ones that I listed

what is on my car is small block clam shells, and I have big block motor mounts, I need small block motor mounts, or I need to find a set of big block clam shells.

I fixed my above message to read correctly.

Thanks
Bud