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Discussion Starter #1
hey guys, i have a question or two. i'd like to start building up a 4.2L engine. I'd like to keep it a single port(dont want to mess w/ IMRC's and such. Heres my questions.

1. Sc block is stronger, so can I use a 4.2L crank in a sc block, and is the 4.2L crank stronger than the Sc's(Is it forged?)

2. Can I use 96/97 NA heads on a supercoupe block? as long as I use the 96/97 upper/lower intake.

3. can I get a set of aftermarket pistons/rods for a a 3.8, and use it with the 4.2L crank(will it bolt up fine?)



I'm going to buy all the parts, and have someone put me a short block together, and I'll put the cam/heads, ect together(I dont feel comfortable with the crank,rods, pistons, etc....I have never done that.

If I go with a strong set of rods/pistons, can I run a 100-125HP shot with upgraded injectors, and pump?
 

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1. From what Ive gathered you need to have the crank journals line honed. The middle one is a smaller diameter so NA and SC cranks wouldnt get confused at the factory.

2. Yes.

3. You will need to use 4.2 rods and pistons or 96-97 rods and pistons. Aftermarket rods for those applications will work.
 

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Discussion Starter #4
bowez said:
There is no need to use a SC block over a 96+, espically on just a stroker, the only difference is the rotating assembly.
http://www.supersixmotorsports.com/PDF/InternalsComparison.pdf

If what you want is a 4.2 just go to the junkyard and get ya one out of a F150.

I'd like to eventually run a power adder of some sort, possibly a m90 from a supercoupe, or a nitrious shot.

I dont want to mess w/ the split port parts or IMRC's...Could I put ported single port heads/intake on a 4.2L block?
 

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yes.
 

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Yes but port them or your swap will yeild VERY small gains.
 

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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.

-Thomas
 
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