Vortech kit engine build dilema


New Member
Oct 16, 2006
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Hi all,

Well the other day I closed a great deal on a V1 S trim kit with a power pipe! :banana:

Now however I have a slight dilema. I have two ways of building my motor. 1) Stock npi heads, PI/aftermarket manifold, Crower/HP blowercams, exhaust, other boltons. Or 2) PI swap, boltons.

I am now leaning twords the Npi build, due to the increased compression that accompanies a swap. I also think that I can achieve my rwhp goals more precisly with the Npi build. I want 360-380rwhp. I think that with the power pipe and higher comp the PI swap will be too much for my application.

Any thoughts?



Mar 22, 2006
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I was in your same dilemma no less than 2 months ago. I have a full bolt on 1997 GT. I wanted more power, so it was either do a PI swap or slap on a blower. My goals for the car are 380-400rwhp...I currently have full bolt ons and here is what i plan to do to reach my goals, i currently have sitting in my garage a V2 SQ trim mongoose kit with MPH boost pipe. I also plan to:
PI Intake Manifold
Custom Grind Blower Cams
Paxton A/A Intercooler
(If i have room before reaching my limits)...lower the pulley size

I plan to do this to my full bolt on 97 with hopes of upper 300 rwhp...you are pretty much in the same boat as me. Let me know if you have any questions.


Jun 25, 2006
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i think your best bet to make the power you are shooting for would be to just swap in an entire PI motor, i know of a guy that just had a V2 installed on an 01 GT with the only other mod being welded in flows and he made 371RWHP with a tune by Tim at MPH.... :pimp:


Well-Known Member
Jan 2, 2007
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You can get 350hp out of the npi motor with a blower. How long that motor will last i dunno. Mine lasted a yr. If you do the swap and add the blower you will have to keep the boost low because of comp. Theres a company here in NJ that can build you a forged PI motor with 9:1 comp. I paid $6820.00 for the motor, new alum. flywheel, motor mounts, PI intake, water pump, AND installed in 4 days. I allready had the blower and boltons on there. You could get the motor and have it shipped to you for sure. Then either have it installed or put it in yourself. The high compression with the swap will blow headgaskets all day long. And eventually your rotating assembly with any kind of good boost. If your interested pm me and i will give you all the info.

Here is the motor i got:

4.6 P.I. engine components(specs)

• Production 4.6 Romeo block, studded mains, bored and stress-plate honed .020( 3.571)
• New factory Cobra steel crank
• Eagle H-beam rods with ARP 2000 bolts
• Probe 18cc dish forged piston (9.1:1)
• Factory P.I. cylinder heads with 44cc chamber
• Factory P.I. camshafts 192/184 duration @.050 .535/.505 lift
• ARP head stud kit and MLS Fel-Pro head gaskets
• Balanced rotating assembly +/- 1 gram

These are the additional parts and services featured on this engine.
Everything else is remanufactured to stock specs (bearing clearances etc…)

I think you end up with a 295ci after the bore. You can downsize your pulley and far exceed your 380hp goals. The motor is rated to 1000hp. You should have no problem getting 450hp out of it.

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