MyFX4Project

Pretty aure gt500 heads are different than navi heads. I've heard navi heads are the best because the ports are the biggest and they flow better than the other heads. The problem is that the stock navi intake is good up to a certain rpm so people running turbos or s/cs can't use the stock navi intake. Tough world when u make over 500 hp lol

Reddragon1260

My friend tom is an ER RN that has been working for many years. He has nothing better to do with his money so he buys cars and parts. He has 3 2003 cobras, a red, white, and yellow. He got bored one day and his son wanted a new car. They went out and found a 95 Supra turbo and bought it straight out. He liked the ride so much he went out and bought 2 95s, one turbo and one NA then bought a red 98 Turbo targa. So that is six cars not including the 86 Grand National and his 97 F150 daily driver / workhorse.

I have WAY to many friends like that, that were part of a mustang club down here.

Carcrazygts2

The 06/07 Gt500 lower is a direct match to the 01-03 Navi heads once gasket matched.

fordmotorsport

Really? I didn't know that

Carcrazygts2

Yep really..

Reddragon1260

well after searching the web the 96-99 and 01 cobra, 03-04 cobra, and FR500 heads are the same. The 99-04 Navi, 02 blackwood, 07-13 GT500, and 06-07 Ford GT are the same head. And the 00 Cobra R is a HIGHLY custom version of the 00 Navi head.

(please note the heads are the same in dimension and bolt pattern, some modifications to castings have been done by ford over the years so they are not EXACT matches across the board)

The #1 and 1.2 heads are the 95 Prototype A head and the 00 Cobra R head. The only problem is Ford never produced the Prototype A head, i believe a version of the head was used on the 97 Super Stallion but that is about it.
The Cobra R head is also tricky as it is kind of like the old 427 SOHC engines in that it used a valve-train specially designed for that engine. If you want the Cobra R heads to work then you would need to do some machining for everything to fit or find someone with either a wrecked 00 Cobra R or a spare engine sitting around which Ford only made a limited amount and they were set aside for race teams only as spare parts.

Reddragon1260

oh and the downside to the navi head is the small exhaust ports compared to the GT500 and Terminator heads. The Navi has bigger intake ports but gets choked at the exhaust side and since the thick center veins have coolant running through them you can not grind too much into them. The GT500 will be a bit more even flowing head.

Carcrazygts2

The navi heads work great under boost. the smaller exhaust port helps create velocity exiting the port..

MyFX4Project

Parts List!!!! (Not 100% final on parts yet)

Main Bearings - http://www.summitracing.com/parts/cle-ms2202p/overview/

Rod Bearings - http://www.modmaxracing.com/product_p/kngcr889hp.htm

Pistons - http://www.modmaxracing.com/product_...d220551f00.htm

Rods (maybe) - http://www.jlpracing.com/1999-2004-5...-beam-rod-set/

Main Studs - http://www.jlpracing.com/1999-2004-5...main-stud-kit/

Side Bolts - http://www.modmaxracing.com/product_p/arp156-5202.htm

Should i reuse my factory dowel pins? Im talking about the little boogers that the side bolts go through into the main bearing cap...

Let me know if you guys have any suggestions as to my parts decisions.

Triton-SAS

Dowel pins normally don't wear and are used to locate parts thus no need to replace them