It's a Datsun 2000, 1970. I have been blocking in 80. What I did on the rockers (I'm slowly learning to do smaller sections instead of getting overwhelmed doing a whole half car) is blocked in 80 until my high spots were poking through, then used body filler on the lows, then another couple coats of epoxy. Once I get the whole rear half done, I'll go back over with finer paper, probably 220, then put one last coat of epoxy just to seal everything until I'm ready for final paint.
This is all after hours, so I don't spend tons and tons of time at once. Once I get things straight, I seal in epoxy. I have the fenders, doors, and hood all ready for their final blocking in finer grits. Once everything is ready, I'll block up to 400 grit, then paint all the panels at once.
I'm just having a hard time figuring out what needs filler, or glaze, or 2K. Maybe I should have sprayed a coat of epoxy, then a coat or 2 of 2k to store parts in, then block & seal, then color.