I have a 1954 Chevy 3100 with a Mustang II suspension with a 1976 Chevy 305 and I am looking to put on a new exhast system. A lot of the headers I have looked at are 1 5/8 inch tubes.
Will the round/oval collectors fit? I think the engine has rectangular exhaust outlets. The plugs are not angled. What exhaust/headers have been used?

Learning as I go, thanks in advance. Don