Generally an engine with hydraulic lifters is quiet running, with no tap, tap sound. With solid lifters, it has a tap, tap sound while running. Sounds like it might be an engine with hydraulic lifters. Is it a low oil pressure engine? A panel truck from 1953 would have had a 216 engine. A sedan delivery (car based)van would have had a 235 engine.
Probably best to get the numbers off the block and post them. Someone here can then tell you what you have.
John
