Iowa Chapter Director
Join Date: Jul 2002
Location: Ames, Iowa
i saw a single port 4.2L NA with a mild cam make something like 170rwhp. The stock heads and intakes will hold you back if they remain stock, so I would suggest upgrading those as well.
The rear main on the sc crank is smaller, but I believe it just uses a larger bearing, I dont think the rear main journal is any smaller.
SC heads and 96+ heads are basically identical, as are the blocks (except for the sc block having a hole in the side for the knock sensor and 'SC' cast into the front of it)
the 96+ connecting rods are the same as 4.2L rods, but the piston height is different, so you will need 4.2L specific pistons.
a 4.2L crank, forged I-beam rods, forged pistons, and ARP head studs could handle a 125 shot of nitrous easily. You could even go 150 or even 175 with a very good dyno tune. I've seen people go 100 shots on stock blocks with a good tune, so putting more into a built engine would not be unsafe. I would go with a nitrous/NA cam if you plan on running nitrous. If you plan to use a supercharger you should go for a mild supercharger cam. so the best thing to dow ould be to figure out what you want to do with the car. a supercharger will want lower compression, around 8.2:1-9:1. Nitrous loves compresison, so 10.5:1-11.5:1 would be the best choice for that.
1988 Notch Mustang: - 438W, direct port n2o, t56
2003 SVT Focus: - SCT X3 tuner