Need part numbers for BB clamshell mounts 1989 R30

[grantpo]

Ok, I have spent several hours of several days google searching and reading. Haven't found concrete answers and have called LMC, Brothers trucks, and Classic Industries with no luck.

What I have is a 1989 Chevy R30 cab&chassis 2wd factory Small block

What I need is GM part # for Big block motor mounts and Clamshell brackets. Mainly need to Clamshell numbers!!!!

I know tons of yall will wont to say use the small block stuff, the truck is a roller so I do not have the sbc mounts. Also read that the BBC mounts are beefier so would rather them since my Motor is 650 hp.

Thanks!!!!