P-Head review

this is long and boring, but for anyone considering a budget buildup, this may be for you.

i decided to install my GT40 P heads that originally came with the explorer engine i installed in my car last fall. i was a bit disappointed with the low end and valvetrain noise on my current setup. so, having just gotten the cobra, i figured i could have the 95 down for a while and take my time.

i took a few pieces off a day. no hurry. then, i put a few pieces on a day. i never had any help. the hardest part was lifting the drivers side head up and over the a/c line and into place. other than that, piece of cake.

i bought a ford head changing kit from summit. the supercharger kit, with better bolt and supposedly tougher gaskets, $99.

i bought MAC 94-95 P headers from central coast mustang. they were $210, and they came with copper gaskets. these headers are probably worth $7. they come with 11mm 3/8 bolts. you cannot access the bolt heads with a wrench once installed. so, i went to sears to buy stainless allen-head bolts. best $15 i ever spent! P heads recess the plugs very deeply, and sort of under the exhaust ports, and as such, you have to use a spark plug wrench that has flats on it for a wrench, because your rachet isn't going to fit onto it because of the closeness of the primaries. i finally figured this out, and it was all good.

started car up, easy. copper gaskets leaked immediately. not necessarily because copper gaskets aren't any good, but because my $210 (worth seven dollars) headers are not true. live and learn. next day, spend $16 on ford OEM explorer exhaust manifold gaskets and 2 1/2 hours later, no leaks.

i have to say, there is no better bang for the buck than P heads. you can find these things for less than $300. (i bought the whole '99 explorer 5.0 for less than $800 with only 6k on the clock.) the power from 2k to 5k has to be 10% better than my current setup, with NO OTHER CHANGES, other than the $210 (seven dollar) headers. if i had known that, i wouldn't have removed the P's from the block in the first place when building the engine originally. that said, perhaps my cam choice wasn't ideal for the ported stockers, and it's a better choice for the P's. the ported stockers made peak power at 5500rpm, but were weak up until 3000. these don't pull much past 5000rpm, but there is torque everywhere now. whatever the case, my car is an absolute BLAST to drive. there is little or no valvetrain noise now, perhaps because the upgraded valvesprings in the old heads put just enough extra strain on whatever valvetrain abnormalities i had. the P springs are stock, only good for sub .500 lift, but the Steeda cam has only .480 with 1.6 rockers, so i'm safe there.

if my tax return is as good as i think, i will have this setup dyno tuned, and compare the numbers to my last dyno graph. the previous setup yielded 250/280 on a dynojet dyno. but, whatever the numbers, i guess i don't care....more fun is more fun.

yes, i imagine if i had gone the custom cam route, or at least carefully chose a cam for either head, both would perform better. live and learn. i do not, however, see going through the work to change the cam. it's fun to drive. since this is a paid-for daily driver, another engine may be in order in the future.

imyourzero, it was really only a matter of labor for me. i already had the heads. all i needed to buy was the headers and the headchange kit, and i already had the other heads and headers sold, which more than took care of the bill. they may very well be within a few hp's of one another, but the area under the curve is NOT the same

and as an added bonus, i drove a 200 mile highway trip today...averaging 24mpg...if i got 20mpg with the old setup, i was lucky. i don't care about milage, but it's a nice extra.

setup....P's with stock springs and valves, stock stamped rockers, cobra intake, steeda #19 cam, pulleys, 75mm Pro-M, 65mm FMS t-body, 3.73's, MAC P-headers, BBK xpipe w/cats, Dynomax SuperTurbo catback.

old setup...ported E7's with upgraded .550 lift springs, BBK shorty headers...the rest was exactly the same.

it's just morbid curiousity, but i DO want to compare dyno graphs. given what ported E7's cost if you buy them (as opposed to doing it yourself), the P's are a bargain, especially if you had planned on getting aftermarket headers already.

oh, and by the way...you can bolt your smog tube to the back of the P heads. the tube wont do anything, but if you have to pass a visual, you can attach it all with no problem...just make sure you plug all the air lines or gut the smog pump.