3/8 push rods

I’d say if the 3/8 pushrods fit your heads without having to grind them to fit, run em. Same for the HD stamped rockers. Higher rpm and spring pressure (not that you have that much) could cause the stockers to bend, but I wouldn’t want to find that out the hard way.

With that said, I put OOTB speedmaster heads on my rebuilt 360, with a mild cam, well I wouldn’t even call it a cam. Lol. I used stock rockers and pushrods, just bolted it all together. I ran that engine for a few thousand miles, revving the hell outofit unnecessarily in my 74 power wagon. Lol

did fine till I blew a head gasket, which I think too high of compression with CA **** gas and detonation was at fault.

I think you’ll be fine either way. I’m not much help. Sorry.