Originally Posted by Jeffrey
Don't know why SMB would use metric fasteners on an american made vehicle converted in the USA?
I think the OP is referring to the bolts used to secure the stock bench seats from the factory, not the SMB installed benches. The bolts are metric and screw into metric threaded holes in the van floor normally with TORX 55 bolts.
Somewhere back in the mid 1970's the US automotive industry started incorporating metric fasteners into the cars and engines. Not everything on the vehicle was metric but a mixture of metric and SAE which kept things fun!