For Safety
Boxing simply reinforces the frame so shorter motor mounts can be used. Hauling 10K means little in this case, we're talking motor mounts. Bob wanted to know who sells mounts and if you wish to bolt those mounts in situ then do so. That's not the issue. I'd use grade 8 bolts cause they don't cost that much more. I merely suggested to BOX the frame cause the 292 has side offset mounts... no front mount.
I also think that once the engine is in the correct setting w/ mounts attached it's easier to tack weld the mounts in situ. Mocking up holes and drilling then resetting the engine and bolting is more to do and that's fine also.
Bob you might also try::
http://www.chassisengineeringinc.com/engine_mounts.htm Cushion Set C.E. designed for street rod use. Space age material is far superior to rubber. Impervious to gas and oil. Greater shock and sound absorption. Greatly increased resistance to deformation and temperature extremes. Thru bolt construction for safety. Larger cross section to support heavier engines. Mount will replace 1932 to 1948 on Chevy/Ford engine mounts. Then incorperate the cushion set mounts.
and w/ the 292 he can haul 10K w/ no problems....
my 2 cents
