Discussion Starter · #1 ·
I am installing a ZZ454 crate next mth and want to get my new hedman mid length heddars jet hot coated before i install everything but jet hot tells me it might be a waste to do it before breaking in engine becuase over 1250 degrees will mess up the coating. I do not want to break in engine and then have to install headers after engine is in place if at all possible. Any advice or experience with this? My 67 chevelle new ZZ 454 is naturally aspirated, no power boosters or anything like that. Its street only and i drive it all the time. I cant imagine heddars will get above 1250 degrees during break in unless i got the timing way off or carb too lean? Need some experienced advice please.