Do they both bolt right up? Any special adaptations or spacers, etc needed for either? One better than another?
RedCoupe92 said:85 SS is right, they are a direct bolt up, the exhaust bump is the only difference, they both flow the same, and I am pretty sure they accept the same headers as the regular gt-40 heads. i had a set of the first gt-40 cast iron heads, wish i would have kept them, they are alot better than the stock heads. either way, you will make about the same power, i believe the "p" heads just replaced the old heads.
85_SS_302_Coupe said:They're direct bolt on but there are issues with typical shorty headers not being able to clear the spark plugs. I'm pretty sure MAC sells a pair of shorties specifically for these heads, if not i know FRPP does. Most full length headers will clear the plugs though because they come straight out from the head further than shorties do.
darthcual said:Yes I believe mac is the only header that will work w/ the p heads. Also they make a higher compression do to smaller valves than the sed gt40.
Car RamRod said:but anyway, for the most part, will long tubes fit on P heads? Anyone here actually using long tubes on p's? thanks