No wonder it blew up, Ford parts on chevy just dont work.Used on flathead fords until 1948. More or less coincided with Henry fords passing. They got rid of the”studs” moved the distributor from between the water pumps to the top (post hole) water outlets from the center of the heads to the front and bunches of other stuff...all intended to cheapen the product. Again back on point split nuts used on ford flatties until 1948 at least.
I've seen them also on connecting rods, just don't remember which engines. Maybe Ford small block?I swear I have seen rod bolt nuts like those, I'll keep locking.