arcticman37

That would be 1999, 98 was the last year of the non-PI mustang. But yes the first runner on the intake manifold was revised in 2001 due to cracks and coolant leaks.

Chubstang

99+ got the PI heads/intake

Quick Shot xMLx

Um no, PI heads were introduced in 99 with the start of this body style so that's a negative. No real difference between the years besides the hood and the transmission(T45 vs. 3650 don't worry they both suck equally lol).

MU71L4710N

the erlier ones had slightly different interior placement (erly meaning before 01.5). defroster was located on the left of the steering wheel, fog light button was on the center console between the seats, stupid stuff like that. they changed it to under the radio in the bezel on the later ones. the early ones had the plastic coolant crossover and had a different waterpump? pulley...maybe its the crank pulley. thats why when u order underdrives they are either for 99-01 or 01-04. cosmetic differences like the side scoops, hood scoops, etc... t45 to 3650 tranny and yes both suck. umm, other than that i cant think of much. theres really not much difference, i would still shoot for an 01.5+ just cuz of the little things but really its nothing to lose sleep over.

Burtonsnow157

this is straight from americanmuscle.com in the description of the p.i intake

Mjaga251

aside from everything else said here, the compression ratio. I can't remember the exact nmbers off the top of my head....anyone?

mustangman36578

the heads in the 99-01 had 4 threads for the spark plugs which caused a lot of the GT's to blow a spark plug out of the head. im pretty sure in 02 they changed it to 6 threads solving the problem.

gt96stang

That is because they didn't start putting on the alum xover until '01[sm=smiley20.gif][sm=smiley20.gif]

99-00 had the crappy all plastic PI intakes.

Aereon

There is a debate on the years but there are mustang gt's with windsor and romeo blocks, I have heard that its in the vin but it is not confirmed.

I am in the process of trying to confirm this, I need to find out if I have an 8 or 6 bolt for my tranny swap^^.

techsent

"That is because they didn't start putting on the alum xover until '01[sm=smiley20.gif][sm=smiley20.gif]

99-00 had the crappy all plastic PI intakes."




Just reading this, makes me want to upgrade. What do you guys suggest?