i have a blob sti with a forged 2.5 + gt30 running 430bhp and i want to change the plugs,i know on the 2.0 it was ngkpfr7b-is it the same for the 2.5?

cheers

 

Depends on what heads you have fitted, 2.0 or 2.5, as the plugs are a different length.

 

all i know it has the avcs heads,i will remove a plug to find out

 

just had a look through the history and when the engine was built they used ngkpfr7b so im guessing its 2.0 heads

will double check anyway

 

Look for the head casting number under where the breather outlets are on the cam covers, if 2.5 it will have 25B or 25D, if 2.0 it will probably be RHS OR LHS 20, not always a reliable way with whats in there now, had a few 2.5's with 2.0 length plugs fitted over the years.