Probably a couple of year ago, already, there was a thread on certain forum and an argument regarding 57 and 58 intake gaskets.. Someone was claiming the 2 barrel engine ( for 57 and 58) took a different intake gasket for a "smaller ported head" claiming theres was a different cylinder head for the 2 barrel engine.. This is false. Here's a pair of 58 heads off a virgin low mileage 58 2 barrel 364.. All cylinder heads were the same from 57 to 59. 57 and 58 had smaller exhaust valves and lower spring install height.. Then in 59, they used the same casting as the 57-58 but put the later/larger exhaust valves in there, with taller spring install height to accommodate more lift since the 401 just came out. (You can easily essentially turn any 57 or 58 head into a 59 by using the later valves) The 59 cylinder head and valves were the same size as the 60 and later except they changed the water temp sender to pipe thread instead of straight thread, starting in 1960. there is only one 57 to 66 intake gasket pattern. reason for this mention is we get calls about this from time to time
