SBC into 80 Cutlass motor mount issues - need help

[64nailhead]

My son just purchased an 80 Cutlass that we are attempting to put a turbo SBC with TPI 327 into. We purchased a new set of motor moounts for an 80 Monte Carlo and grabbed a set of clam shells off from ebay. The issue is the clam shell bolt holes doesn't line up with motor(frame) mount. Question - are all clam shells the same? The motor mounts appear to be exactly the same as the worn out one we took out. If the clam shells are different, then what year do we need? I assume they must be from a G-Body.

HELP and any and all is greatly appreciated - Jim

 

[t01blaze]

Are the mounts upside down on the frame?

My son just purchased an 80 Cutlass that we are attempting to put a turbo SBC with TPI 327 into. We purchased a new set of motor moounts for an 80 Monte Carlo and grabbed a set of clam shells off from ebay. The issue is the clam shell bolt holes doesn't line up with motor(frame) mount. Question - are all clam shells the same? The motor mounts appear to be exactly the same as the worn out one we took out. If the clam shells are different, then what year do we need? I assume they must be from a G-Body.

HELP and any and all is greatly appreciated - Jim

 

[64nailhead]

Are the mounts upside down on the frame?

Don't believe so, as I don't believe they will mount if flippled over 180 degrees. The bolts holes on the upper side are wider/farther apart than the lower holes. Also, it doesn't appear that they can be mounted the crossmember higher or farther apart than they are presently. Any pics of how they are suppose to mount? Syoill, seems like the clam shells are out of whack - I'm assuming they are not all the same just looking for confirmation.

 

[Doug Trahan]

Don't believe so, as I don't believe they will mount if flippled over 180 degrees. The bolts holes on the upper side are wider/farther apart than the lower holes. Also, it doesn't appear that they can be mounted the crossmember higher or farther apart than they are presently. Any pics of how they are suppose to mount? Syoill, seems like the clam shells are out of whack - I'm assuming they are not all the same just looking for confirmation.

I have installed several SBC engines in the Regal`s which should be the same as the Cutlass. There are several holes drilled in the frames on these. Note: There are only 3 of the four mounting holes used on the brackets that bolt to the frame, the lower front does not get used. This was my experience anyway.

 

[HAFROD]

Here's some pics of the RH small chevy motor mounts on the chassis. This is on my 78 Cutlass. Notice the motor mount on the chassis hangs off on the bottom front corner. Only 3 bolts are used.

 

[HAFROD]

I'm not 100% positive, but I think that truck upper clam shells are taller causing the engine to sit up higher. I read or heard this and cannot speak from experience

 

[64nailhead]

I'm not 100% positive, but I think that truck upper clam shells are taller causing the engine to sit up higher. I read or heard this and cannot speak from experience

Our clam shells are deeper than the ones in your pictures. I'm pretty confident that is the issue. The local pick-n-pull has an '84 and '79 Monte Carlo. I guess I'll be grabbing them. Thanks greatly - you solved my dilemma. Unfortunately I won't be able to test fit the header and weld up the crossover until I get the correct clam shells. Thanks again - Jim

 

[Kwik_Cutty88]

I'm not 100% positive, but I think that truck upper clam shells are taller causing the engine to sit up higher. I read or heard this and cannot speak from experience

You are correct, the first motor I did we used truck clamshell mounts and didn't know it. This caused the engine to sit up higher and at a weird angle (which we thought was normal at the time.) It ended up breaking 2 transmisson bell housings in 20,000 miles. After we built another motor and changed the mounts all has been good. Rule of them if the motor is a b*tch to get it, Sometbing is probably wrong. These cars should be super simple to drop an SBC in if all the parts are correct.

 

[64nailhead]

You are correct, the first motor I did we used truck clamshell mounts and didn't know it. This caused the engine to sit up higher and at a weird angle (which we thought was normal at the time.) It ended up breaking 2 transmisson bell housings in 20,000 miles. After we built another motor and changed the mounts all has been good. Rule of them if the motor is a b*tch to get it, Sometbing is probably wrong. These cars should be super simple to drop an SBC in if all the parts are correct.

Thanks. It appeared that the motor should drop in easy and when it didn't I figured something was up. Thanks for the input - breaking the transmission would be a moment of sadness.

 

[64nailhead]

Here's what I found. I thought I had the incorrect clam shells, but as it turned out I didn't. I had to elongate the mount bolt holes in the frame by 3/8", on both sides of course. I'm sure that the motor sits 1/4"-3/4" higher. Hopefully it doesn't creat a tunnel issue, but if it does I'll expect I'll have to modify a set of clam shells. The motor is level in the car, but I don't know if the frame is tweeked or if this could just be the situation. Hopefully we'll have the transmission test fitted today and the crossmember modified for the 200-4R.

FWIW, I'd like to put a thanks out to UMI Performance, as their website was the only place I could find the correct dimensions of the motor mount and clam shell. I would've bought a set of the their solid mounts if I needed them just for the assistance that their drawing provided.