Explorer intake swap now or later?
Reply #9 –
With the GT-40 or GT40-P heads, there's plenty of difference. I have P heads on my car, big difference. Mine are ported with Trick Flow springs, but the power increase was noticeable. The P heads can be found cheaper than the GT40 heads, but they are better than the GT40's. People are scared of them due to the revised plug angle. I use BBK unequal length shorty headers with 90 degree plug boots and shorter plug on the number 7 cylinder. No issues at all.