WJL

Great post, I am new here too, hoping to soon be a new owner of a 2001 GT with a 1989 5.0 in it. I hope this is the right place to post this but here goes. I have become fascinated with the 4.6l modular motor and have read as much info as I could find. I would one day like to put the 4.6l back in the 01 GT using junkyard Ford parts. Would it be best to use a 96 - 97 NPI bottom end with 99 – 05 heads and intake or just go for the 01 PI motor. From what I have read the NPI bottom end with the PI top will give you a higher compression ratio than the 01 PI motor?

jdmeaux1952

Putting stock PI heads on a NPI bottom end will kick the compression to around 10.95 to 1, which will need at least 91 octane with a mild tune or 93 octane (or higher) with any other aggressive tune. But then if you decide to add force induction, you will kill the bottom end. And it won't take too much of a tune to cause serious problems with the pistons. (I learned that the hard way.)

BowtieBrother

I like the article but for one thing. A bigger throttle body on a stock application wont do much for hp. All a bigger throttle body will do is increase throttle response. Bigger throttle body does so by well being bigger meaning less restriction. In order to get any hp gain you'd have to port the intake and heads or just purchase better flowing units. The only way to over come the CFM restrictions is to FORCE the air in.

tadpole1969

yup agree with you on that! just installed the 78mm bkk throttle body and noticeable throttle responce inprovement for sure! may have a slight hp gain but not nothing to big

Tipsy Bojangles

I would do Subframes first, but only because I got my car with them. I understand they are a pain to install, but well worth stiffening up what is basically Fords revision of a '79 chassis... The consensus is usually suspension/brakes first, speed later. And as far as cold air intakes go, unless you buy one for a larger throttle body or other mods, it's a little unnecessary. Mustangs basically have a CAI from factory since '87.. Not to belittle where others spend their money, I agree they look great, but don't net you worthwhile gains if that is what you're after. Just get a K&N filter and call it a day. I'd appreciate input from y'all as well, I don't pretend my personal opinion is a hard and fast rule to live by, and have yet to do most of what has been mentioned here

98TripleBlackGT

MCxQubed, Thanks for posting this. I just picked-up a '98 GT and although I plan to keep it (mostly) stock, there are a couple of items on that list I plan to work through...Thanks again!

TylerHartt

Very helpful post, I've already read all of this but I can imagine it'd be very helpful.

sotom1

Great post, even for a guy that's done a few mods, there were a couple of gems I took away. Thanks.

01GTon18s

Thanks for the info. I just bought my mustang less than 2 weeks ago, and it already had an eibach performance suspension on it. Everything else is stock and I was going to start with a CAI but after reading your post I don't think I'm going to worry about that. I do want to change the exhaust but more for a deeper sound than anything else. I haven't had time to research this yet so I don't know what I'm going to go with.
If you had to pick one mod off your list to start, what one would you pick?

Soldier GT

Gears, Gears Gears.... Completely Stock? Go with 410's! It will be a totally different car...