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Author Topic:   Pistons to work with N351 heads
d4490
Dirt Maniac

Total posts: 143
posted December 09, 2004 03:50 PM  
I have a existing 351w short block that has a Scat 3.85 stroke crank, stock rods, and Speed Pro forged 302 pistons. The pistons are set at 0.000 deck height, and have the 4 valve reliefs. The heads I had on them last year are the D0OE castings with stock size valves. Next year our track will allow us to run headers and aluminum intakes. I want to switch to the n351/352 heads. Will I need new pistons, or have to cut new valve reliefs? What size cam can I get away with and still use these pistons? The crank is balanced, and I don't want to balance it again if I don't have to.

outlawstock17
Dirt Forum Champ
Total posts: 1363
posted December 09, 2004 05:12 PM  
no, you can run up to about .650" lift with the N heads without any valve notches. they make N head specific pistons that are true flat tops without valve reliefs. the N head is a 10 degree head so the valves are almost parallel with the cylinder. tons of clearance. you will need a special valve cover with a kickout to clear the N head valve springs. they're about $70-$100 a set. you will love those N heads!

another thing to consider....i've run that exact combination you're building. it had so much torque i could never get it to hook up good. i put the N heads on a long rod, stock stroke 351W and that engine performed much better. i still have that long rod engine and it is still complete. it has a lot of good stuff in it including a big roller cam. $3500 and it's yours.

[This message has been edited by outlawstock17 (edited December 09, 2004).]

d4490
Dirt Maniac

Total posts: 143
posted December 10, 2004 06:03 AM  
Outlaw, what camshaft, intake and headers did you run in your stroker? I'm having a hard time finding a header manufacturer that has a header to fit a 351w into a Crown Vic.(3200 lb with modified stock 4 bar setup) The motor is set back with the #1 spark plug (r.h. front, more set back then a chevy) with the upper ball joint, and the firewall is out of a 77-79 T-Bird. The firewall is set at the mounting flange of the bellhousing and the block.

I was looking at running the Torquer II intake, I don't think I need to turn the motor to hard at my track, 3/8 med. banked track. If I ran at a 1/2 mile I would run the Victor Jr. Am I thinking correctly?

I am also looking a building a 331 stroker, I have a .030 over 302 sitting on my shop floor. What would you recommend for the camshaft and intake on that engine. It may be used in a street stock and a modified.

[This message has been edited by d4490 (edited December 10, 2004).]

outlawstock17
Dirt Forum Champ
Total posts: 1363
posted December 10, 2004 06:30 AM  
schoenfeld makes the headers you need. part # 386N fits the N heads. # 386 fits stock heads. they're about $200 a set.

i ran a victor jr., 830 holley and a small solid cam (250 duration @ .050") in my 393. don't turn a 393 stroker over 6500 unless you have high dollar internals.

the 331 will like a roller cam with about 260 duration @ .050". victor jr. and 750 carburetor. you should be able to turn it close to 8000.

to use the N heads on a 302 block you will need to modify the pushrod holes in the head or use an offset lifter.

[This message has been edited by outlawstock17 (edited December 10, 2004).]

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