88vertSC

iTrader: (1)

Stock Lq4 bottom end, L92's milled .030 (64cc, stock LS3 valves, PRC .650 springs) and TSP 224r cam. I will of course still measure, but Im wondering if anyone knows how close Ill be? Anyone running something similar that had to flycut? I'm looking to avoid that, if at all possible.

Other question is what should my compression run? Trying to keep it to 10.5 or under.

Thanks

Chi_weezy

You find an answer to this? I'm in a similar boat. I'm wanting to get the l92/ls3 heads for my lq4 but TSP suggested not to run those heads because my CR will be too low, around 9.6 or so. So now I'm wondering if I should get them milled, or go with some other heads that they offer. They suggested their stage 2.5 5.3l for my 6.0l lq4. Said they would put me at about 10.6:1 with a good sized cam

yonerhottlt1

iTrader: (21)

As you already know, it's always best to measure. But I don't see any problem at all with that cam clearing. However, I do not think that running that single pattern cam will be a good idea with the square port heads but that's just my 2 cents.

Alvin@PCMofNC

I'm with TSP on this one. You can take quite a bit off those heads and still not get them where you want to be with that setup on compression ratio. I'd say steer torwards a set of worked 243's or better.

low2001gmc

iTrader: (148)

there are plenty lq4 builds with l92 heads on here. an lq4 has 9.4:1 cr with stock 317s which have an approx 71cc practically same as 70cc l92 heads. you can mill the heads .030 to approximately 64cc as stated and raise compression from 9.4:1 to at least 10.2:1 cr which is below your 10.5:1 goal. i would recommend a 224-230, 581-591 on a 113 or 114lsa split duration cam to be more optimal and still clear. these should provide you a torquey motor making about 445 hp. if i can further assist you, just pm me.

bloodhoundz28

I have a 416 fully built stroker with ported L92 heads and i'm considering having my heads milled. Is it worth the gains?

Alvin@PCMofNC

It's definitely OK to deck the heads to get them where you want to be but those heads really like compression. My point is a 10.5:1 is a minimum compression ratio for a good NA LS3 headed engine.

Tainted

iTrader: (9)

either go cathedral, or flycut those pistons and mill those heads down. 10.5 is a minimum