Compression w/ PI Head Swap???


New Member
Apr 28, 2004
I'm about to do the PI head/intake swap and some comp blower cams on my 97 GT mustang and heard that it will raise my compression up to 10 to whatever compression. Is there anything I can do to lower the compression down since I am running a blower and dont want my motor to blow? Port heads maybe? What would be the best cam for my car if not a comp one? Thanks for your time.
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the compression ratio goes up to around 10.65:1 i believe. in MM&FF last month they had a company port heads who also shaved the combustion chambers making them bigger, therefore the CI dropped. if you really want to you could also consider rebuilding the shortblock and getting some dish pistons. that will help keep the CI low and allow you to run some more boost.
Remove the Swirl dams. Not sure how much that lowers the compression though. I was curious about the whole headswap or P&P NPI heads with a S/C a while back. Everyone said that I should P&P the NPI heads if I was going to get blown.