273 Mystery Motor

Pushrods were for all 273 engines from 1964 thru 1967. Then they went to the easier and cheaper hydraulic rockers and valvetrain. No big deal. Buy some valve cover gaskets, remove five 1/4 in bolts with a 7/16 socket, pull one cover, take some pictures. Easy to tell. Yes, the E-4 cam can be used with either piston configurations. Just be sure to check the timing chain and get 340 valve springs or equivalent, so that 273 can sing.