Larrys'66

Thanks Joe

Yes, I clearly bought the wrong ones, twice in a row. The first mounts I ordered were to specific to replace the 330 mounts and match to the existing pads. What arrived was entirely the wrong shape and had threaded studs. For the second set, I asked for a mount found on a '72 455 Cutlass and these looked right at first glance, but I was wrong...

It appears the mounts I am using did little more than hold up a rebuilt engine for several years. They are in now and I will keep an eye on them.

joe_padavano

Unfortunately, nearly all of the motor mount catalogs have the applications wrong. This is why I always order by P/N. The mounts with threaded studs are 1965-50 full size only, and are different RH/LH. Your 66 needs 2261s to match the frame mounts. This thread should be on speed dial.

JCMC64

Late to the party, but what Joe said was my thoughts exactly.

Larrys'66

Maybe we need a new section on the forum labeled "Speed dial". The seasoned Olds folks already have a good idea what questions are reoccurring and probably could place bets on where in the build they will surface.

Then again, we need to learn some things the hard way too...

Thanks to those who share their experience....

jensenracing77

On the same note... It was just brought to my attention that all the motor mounts for the 455 frame pads are not drilled in the correct spot. Has anyone had alignment issues with the mounts for the 455 frame pads? I compared my NOS 455 mounts to a set from inline tube and a set from the parts store and both sets were 1/4 inch off from the NOS.

joe_padavano

Drilled where? I've had problems with the Chinesium Anchor 2328 mounts where the holes for the bolts to the block were off. A die grinder fixed that.

jensenracing77

I put an all thread across all of them on the frame pad side. The engine side on both aftermarket sets are approximately 1/4 inch off. I will likely just do the same with a die grinder when I use them.

joe_padavano

Yes, that's exactly what I found. Interestingly, I bought a pair from the auto parts store and only one had this problem. Like I said, these were Anchor 2328s from Advance.

oldsfromyell

Trans Dapt has an Oldsmobile mount #9592. Does anyone know if they are the same height as the SB or BB mount.

joe_padavano

It appears that these mounts are designed to work with the TransDapt universal crossmember, so they don't say which height the mounts are. And as always, let's please stop calling them BB and SB mounts. The 2261 "small block" mounts were used with the big block until 1969, and the 2328 "big block" mounts are used on the 307 cars.

Gianni71Cutlass

Hi all. I am swapping out my 350 to a 455. I understand you cant mix up the mounts. My question is if I use 350 motor mounts with the 350 frame mounts, will the 455 engine sit up higher? if so how much?

RetroRanger

No the engine is at the same height! I have a 455 w 350 MTs in my car w no issues

joe_padavano

SEARCH is still your friend. PLEASE read this thread.

Short answer is that the CRANK CENTERLINE will be in EXACTLY the same place, which is the only place it can be. The 455 is physically taller than the 350, so yes, the valve covers and carb will be higher. This is exactly how it was from the factory.

ELY442

Does these bolts suppose to have lock washers or just plain washers?

joe_padavano

The CSM actually shows both a flat washer and a lock washer, except where the motor mount heat shield is used - the flat washer is deleted and only the lock washer is used. Apparently the heat shield serves the same purpose as the flat washer.

ELY442

So you mean the heat shield goes in front of the motor mount hole?

joe_padavano

That's what the CSM diagram shows. The mount goes against the block then the heat shield goes against the mount.

ELY442

Its weird that there's only one heat shield that goes only on the drivers side both not both sides. I'm sure there's no problem getting another heat shield to add one to the passenger side.

joe_padavano

That's probably a function of how tight it is on the driver's side. Steering box, starter, etc, plus a more "compact" manifold on that side. The RH mount is comparatively wide open and not subject to as much heat. GM doesn't add parts (and cost) where not needed.