96 Gt, PI swap, Hitech Stage 2 cam. Will it work?

94GTHO

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Jul 21, 2005
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Richmond, Va
I have a 1996 Mustang Gt and its getting time to replace the heads because some of my seals are leaking a bit. I was planning on doing the PI swap because thats a no brainer. But my real question is, can I use Hitech Stage 2 cams. I would be getting new chains, guides, and tensioners just to be safe and I will get the cams degreed correctly with a good tune. I just know that 99-04 heads on a 96-98 shortblock has higher compression than a regular 99-04 motor or so I am told. I just really dont want to spend alot of money just to find out I will need to build the bottom end too or end up just doing a 99-04 longblock.
 
If your compression is good and you don't plan on spinning too much past the factory redline, then aside from possibly needing to notch the pistons, your current shortblock should be just fine.

You will get a bump in compression with PI heads on an NPI shortblock because PI heads have a smaller combustion chamber but PI pistons have a deeper dish to compensate. The difference in pistons doesn't make a difference in valve clearance though, because the valves would hit on the rim of the piston which is at the same level on either piston and not the dished center area.
 
costs a bunch more, but trick flow has a nice set of heads that flow well out of the box without any porting. they moved the intake valve so that there is more ptv clearance and you can choose from two combustion chamber volumes.

just an idea, but they are too expensive IMHO.
 
If you ported and rebuilt your NPI heads, you will have alot more cam clearance than a PI head. Aftermarket valves will help with either head. It's basically a toss up between more compression with a PI head or more cam with an NPI head. Do you plan on going FI or staying N/A?
 
They should clear but to be safe go with some aftermarket valves that don't have as thick of a face. Degree the cams if you can or if not get some of those matched cam gears nickmickinley sells. spin the motor by hand several times with the plugs out so if it's going to hit it will do it then.

The part of the valve that hits on our cars is past the dish on the dished pistons that is on a true PI motor so what clears on a regular PI motor should clear on a PI head swapped NPI car.