I've modified cross memebers to use this style chevy mount. Had one in my race car for 11 years. The bolt spread is a little off but the welder and a couple of thick washers fixed that.
https://www.summitracing.com/parts/...mptKI_AIVpBPUAR2mMg8PEAQYBCABEgLw1vD_BwE
Also check energy suspension. GM mounts have either 3 3/4" or 4 1/4" bolt spacing. Some have slotted mounting holes.
https://teamenergysuspension.com/en...-transmission-mounts/transmission-mounts
Doug

Last edited by dvw; 12/20/22 12:53 PM.