[jsn829]

I would measure the frame from all different points to see if it is bent or diamond shaped. To bend an engine crossmember is not to easy and I think you would see more damage to the frame. Are the bolt holes for the engine mount on the frame the same on both sides? There is alot of holes on my frame that are off. If you cannot find anything wrong, I can measure my frame mounts to see if they are different.

[jsn829]

You might have to slot the top holes on both sides to make it fit. Edelbrock says to do this on the 64-67 but 68-72 might need to do this to.

[fbrown]

While it wouldn't take much to make it fit, I worry that the frame might be bent. (Or wasn't repaired correctly in the past) I found a hole in one side of the frame that was elongated and a hole on the other side that had been pushed out. I believe chains may have been attached at these points and the frame straightened. There aren't many measurements in the service manual for the front part of the frame. The distance between the frame rails checks out good. The engine that was installed in the car was installed in the other set of holes on the frame. (3 bolts) Since original engine had already been removed, I don't know if there was a problem when the original engine was removed. I don't know if the set of holes I am using was drilled correctly since they had never been used. From the slight wrinkle in the frame at the steering box, my guess is that side of the car had been hit from the side and may have bent the cross member slightly. Since there was never a engine installed in the other holes, I don't know if the hole locations are off or if the frame is bent.

Some measurements of the distance between the holes from side to side would be really nice if someone could provide them. I have also been searching for the dimensions of the motor mounts the see if mine are too high/thick, since it also appears if the pre-load plate was not installed the engine would fit. I am using Tall frame stands from Goodmark, engine mounts from Energy Suspension and Edelbrock LS1 engine plates.

[jsn829]

Top bolt holes-- at the top of the hole straight across is 19 1/4. Front and back holes are the same. I measured 2 frames and they are the same. This is for the holes that are oval on one side and round on the other. Those were the stock pontiac mount location.

[fbrown]

Thanks for the measurement. My frame is also 19-1/4" as shown in the picture. Maybe my frame is OK and my motor mount problem is cumulative dimensional errors caused by using parts from three different companies.

[fbrown]

Problem is solved. When I measured the Energy Suspension Motor Mounts, I found that one of the mounts was 3/32" taller than the other one. I put both of them in my press and applied a little pressure for a few seconds. Here is the result after reinstalling them.

[fbrown]

I got a transmission filler tube today. I had tried a 2002 Camaro tube and found that the mounting bracket didn't come close to any of the holes on the LS3 cylinder head. This filler tube uses the bell house mount.

BTW the bell house in the photo is not correct for an LS3 engine. I am waiting for the correct tube from my transmission guy.

I have also given up on using the Autokraft oil pan. Although its fits in the car, it doesn't support the transmission bell house like a GM pan will. Almost half of the bell house would not be supported if using the Autokraft pan. I am ordering a Camaro oil pan modified by Street and Performance to fit an A-body.

This tube is a TeckPak K77999U it costs about $30 with shipping