can you use small block engine frame mounts with a big block??? Whats the difference between the two???

Yes SBC mounts are the same size. just have an extra metal on the outer formed edge. The SB mounts have been use by many .

Originally posted by WayneK:
Yes SBC mounts are the same size. just have an extra metal on the outer formed edge. The SB mounts have been use by many . there is a difference in mount height,sbc sits higher off the frame then bb.

there is a difference in mount height,sbc sits
higher off the frame then bb
That explains my problem, I can't get the motor to sit level, trans is as high as it can go without going through the floor. Thanks I thought it was something like that.

Been discussed many times in the past and everyone seems to agree that small block mounts do work on big blocks but...........

If you use the old small block frame stanchions you have to use the matching "other half" (the part that bolts to the engine)

If you use big block motor mounts, you have to use the matching big block frame stanchions.

Also everyone has said that the frame stanchions must be replaced if it was originally was a 307 but not necessary if it was a 350.

If this is for a 66 chevelle, which is in your signature, you have to use small block engine mounts with the small block frame mounts. The engine will not sit too high, I have a 454 on 283 mounts in my 66 convertible.
For 68-72, 307 frame mounts must be used with 307 engine mounts, you do not have to change them. 350/BB mounts are the same. Snowtrav you are obviously new here, but please dont post information that is "heresay" or a guess because all it does is confuse people trying to learn.

It is a 66 and it was a small block powerglide car.Now the problem is that it won't sit level, it tilts about 5 degrees to the rear, now this translates to the fan being closer to the bottom than the top, about 1 to 2 inches. Now drptop70ss says he has a 454 on 283 mounts but he also says that you have to use small block mounts with small block motor mounts?? I use Morosos solid motor mounts will that make a difference? I think they a little taller than factory. Anybody else have any ideas on how to fix this????

Have you compared the solid mounts to a factory mount to see if there is a difference? Are you using the correct height trans mount?

That's where I would start looking. Comparing the Morso mounts with the orginal 283 mounts.
I to have layed out and compaired 66/67 SB and BB and ther the idential Hight. width and center bolt location when mounted off the center cross member. this is for 64/67 ONLY..

The Moroso is the same as factory, I talked to a buddy with a factory 67 big block, we both agreed it looks like his mounts are shorter, so it looks like I'm going to have to fab something or find factory mounts. Thanks for you'alls help. Mike

I would double check the solid mounts first, the "tilted engine" deal seems to be a common complaint here when the solid mounts are used. I also have a factory 66 SS396, and my 396 sits in the engine bay the same as the 454 in the 66 vert.