1fastssnova

Hey everyone, I recently picked up an LQ4 out of a 3500 Express Van. Going to do a rebuild for a Procharger setup. I have a P1SC head unit and plan on a blow-thru carb setup with new pistons and rods with the stock crank. What I can't decide is whether or not I should use the 317 heads that came with this motor or pick up a set of the LS3 (non CNC'd) heads? After some reading it seems as though CNC'd 317's will flow the same as regular LS3's. I am trying to go with a conservative budget, but will always upgrade if spending a little more will make sense in the long run. I've seen several topics here regarding cathedral vs rectangular port, as well as the deck thickness of different factory heads when it comes to boost. I'm shooting for 12lbs of boost and around 600rwhp. I have to do this on pump gas and meth injection. Will the 317's get me there with some head work? Or for around $700 is the money better spent on LS3's brand new in the box. Rebuilding the 317s with head work will probably cost more that.

NemeSS

iTrader: (127)

Keep the 317s. Keep the stock motor. Use ls9 gaskets and a ls9 cam. Use arp studs. Spend ur cash on a tune and fuel system. 12psig is no problem on a stock rotating assembly on a healthy lq4 with everything else in order on pump gas and proper tune and sufficient fuel supply.
Go ahead and upgrade springs also if upgrading cam. No need for ls3 parts. 317s work excellent under pressure.

Bob@BruteSpeed

iTrader: (16)

I'd go with good rods and pistons. What is this going in? Bob

1fastssnova

Def going to do the rods and pistons. Motor is going into a '69 Nova. I have a 468 ci BBC w/ a Procharger in there now with steel heads. I figure I could make the same or more power and take 200lbs off the nose.

monteperformance

So what did you decide to do about the heads? If you haven't decided yet, I would speak to Colin at SK speed in Lindenhurst, not too far from you. He's pretty knowledgeable on this type of stuff.