GT40p port job

frank rymas · 03-27-2002, 09:33 AM

I am going to port my GT40p heads, this motor is mild. B303, shorties, performer intake, holley 600dp, T-5, 3.73 gears........ should I just go with a gasket match, clean the intake side and polish the exhaust side? what do you think?

89 Cobra LX · 03-27-2002, 04:58 PM

Well, I don't have any flow #s for comparison or anything, but I can tell you that my heads have been mildly ported on the intake and exhaust sides. I would at least do enough porting to remove the casting flash. I believe there is a hump in the exhaust port that you will want to smooth out as well.

I've never trapped below 101MPH in the 1/4 mile.... not too bad for some small-valved iron heads.

89 Cobra LX · 03-27-2002, 04:59 PM

What shorty headers are you using? Are they GT-40p specific?

frank rymas · 03-29-2002, 04:23 PM

Yes, GT40 equal-length by MAC, 2.5 inch no cats, flowmaster, with tail pipes

03-27-2002, 09:33 AM	#1
frank rymas Registered Member Join Date: Mar 2002 Location: macomb mi Posts: 4	GT40p port job I am going to port my GT40p heads, this motor is mild. B303, shorties, performer intake, holley 600dp, T-5, 3.73 gears........ should I just go with a gasket match, clean the intake side and polish the exhaust side? what do you think?

03-27-2002, 04:58 PM	#2
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	Well, I don't have any flow #s for comparison or anything, but I can tell you that my heads have been mildly ported on the intake and exhaust sides. I would at least do enough porting to remove the casting flash. I believe there is a hump in the exhaust port that you will want to smooth out as well. I've never trapped below 101MPH in the 1/4 mile.... not too bad for some small-valved iron heads. __________________ Eric - 89 Mustang LX coupe 5 speed 302-Cobra Intake-GT40p heads-TFS stage 1 cam-FRPP 1.6 roller rockers-3:73 gears-KYB shocks and struts-Eibach Pro-kit-HPM Mega-bite upper and lower control arms-FRPP aluminum driveshaft-16x8 Chrome Cobra Rs R.H.C. #14

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03-27-2002, 04:59 PM	#3
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	What shorty headers are you using? Are they GT-40p specific?

03-29-2002, 04:23 PM	#4
frank rymas Registered Member Join Date: Mar 2002 Location: macomb mi Posts: 4	Yes, GT40 equal-length by MAC, 2.5 inch no cats, flowmaster, with tail pipes