78000 mile LQ4 - already torn down, and ready for new oil pump, timing chain, LS7 lifters, lifter trays, cam and heads...

Cam:
Lunati-
2200 - 6800 CAMSHAFT, GM LS VHRX278-12X 278/282 adv. 227/231 @.050 .651/.651 112/108 LSA/ICL

Heads:
Stock LS2 with Lunati matched valve springs, retainers, locks and push rods

I got the heads new with my LQ4 because the manifold bolts were broken in the 317's -- after receiving another set of heads from them with broken manifold bolts, they authorized me to spend $640 for a totally new set of heads. I was very pleased!

So, with the higher compression and better combustion chamber design of the LS2 heads along with the cam I'm using, what do you think? My only concern is PTV clearance, but Lunati has already told me I could return this cam if there are problems for something a little smaller.

The stock truck manifold will be holding me back for a little while, but I'm in too far right now to do the Pro-Flo XT right up front.

Looking to use 1 3/4" headers, duals with X-pipe and ultra-flow 16" mufflers.

Going in a '68 C-10 with a T56.

Power estimates? Dare to guestimate an E/T ?

Previous best was a 14.2 @ 98 with a Gen1 SBC 350 putting out around 400-420 HP or so at the flywheel

 

Like the cam duration but the lift is too much for stock heads and ptv issues...good luck bro...

 

Max lift has ZERO to do with PTV clearance. WWhen your at max lift the piston is a mile away from the valve, and getting farther away in a hurry.

I would still check though PTV though.

The Edel intake will kill your low end and is a total missmatch for your combination. The XT is for light vehicles that live in 5000+ RPM range. There was a guy on here that lost a full second in the 1/8th mile with it in his!!!!

 

Which would you recommend? I'm not totally convinced an LS6 intake is worth the expense, given the flow rate comparison charts I found on this site (at least I think I found them here...)

 

FAST made an intake for trucks too. The 102mm LSXRT, +17-25hp, no losses.

Configurator: http://www.fuelairspark.com/Company/...mSelector.aspx



Dyno Graphs on a stock, and modified engine:

 

Uggg... I think I'll hold my breath waiting for something more affordable. Sure, there are good gains there, but not $1000 gains, IMO of course

 

what i meant to be more specific is that a cam with that much lift would require good proted heads to be optimal and i still think ptv would be an issue. as for intake, the ls6 flows slightly better than the 99-07 classic truck intake. however, the trailblazer ss intake and 07 up nnbs intakes flow better than the truck intake making comparable to the ls6. plus you wouldnt have to change accessory drives so in the end probably just as good as the ls6 and cheaper swap. good luck, rob.

 

They still flow considerably better at .500 than they do at .300, so why not try to keep the valves open at higher lift levels throughout the cycle?

That's my theory anyway. Although I will proceed with caution on the PTV issue.