2mnyvets

I have a 73 BB 4spd that I am doing a frame off restoration on. The car was hit in the left front and the PO repaired it without bringing the frame back to tolerance. The frame goes to the shop Tuesday, and I have the dimensions for the frame from various web sites but I don't have any dimensions showing where to locate the motor mounts and the transmission mount. Does anybody have these dimensions or know where to find them?
Thanks

Alan 71

Hi 2,
Welcome!
First post!!
Have you seen this drawing?
It's gives just some basic information for locating the engine mounts.
Notice the offset to the right side.
There's no difference in the mounts for a bb or sb frame.
Good Luck!
Regards,
Alan

TheSkunkWorks

I'd think a frame shop worth its salt should more than likely have access to a good deal more info than is readily available to the rest of us. So if they're relying on you to do their homework I'd consider shopping a bit more before letting the work. Also, whoever may end up doing it, make sure they triangulate for square not only overall, but within the forward, middle and aft sections as well. IMOE it is entirely possible to have a frame check square overall from one set of diagonal measurements while still having issues that will show up when aligning the suspension. Lastly, I'd remind them that this is a sportscar, after all, so please to minimize just how much tolerance is deemed "acceptable". And, don't be shy about it. My $.02

2mnyvets

Thanks guys. I just got back from Corvettes at Carlisle. It was a good show. Alan, Ya it is my first post, but certainly not my first visit to the site. Thanks for noticing. I was using the drawing that you show and a few other similar ones. What is missing from all of them is the engine and transmission locations. The frame damage is minimal but the most severe is the left engine mount where the mount was obviously pushed forward and that is the dimension that I cannot find to verify.

Skunkworks, I totally agree with you, however I only found one guy locally that had the frame machine and was willing to do it. I took it to the frame guy that "everybody " uses and when I got it back it was out of tolerance. I spent the last three days making fixtures and checking and verifying dimensions. I am taking it back to the guy Tuesday and will stay with him until it is right. I don't have much of a choice.

At this point, I know that the cross member at the transmission mount is up 3/8" with respect to the ends, the left front frame at the spring coil is down 5/16" and the frame is pushed left 5/32" beginning at the S bends. The centerline between the 2 and 3 body mounts is 3/16" closer to the left frame rail than the right. This should correct itself when the front is pulled back to position. I measured diagonals between every body mount and the front and rear work points. The frame is racked in the mid section by 1/4 to 7/16" depending upon location. I also know that the left side engine bracket distorted the frame between the front cross member. Not sure what else I can look at and measuring with a tape measure is not ideal, but I am hoping he has more sophisticated equipment.