Hi readers and posters,
I am looking for some advice on my "budget build" for my 2500hd. I currently have a cam package on order and I'm thinking about adding a set of the PRC LS6 stage 1 heads to the mix. It's not a race truck, just a DD and tow vehicle.

Any idea on the HP gains on the Stg1 heads with slight mill .30 off with the below cam. I currently have the 317's on the truck at 9.5 cr, would going with the stage 1 heads at 10.5cr be in 30-40hp range or 10-20 hp range. I know going up the 1 pt cr will give me about 10hp, but will the stage 1 port job combined with the below cam result in 30-40hp range?

216/220 .560" lift 114lsa

The new Heads, lifters, rods, bolts, gaskets are about $1600 and if I'm only looking at 10-20hp it's probably not worth it... If we're talking 30+ hp it might be worth the expense.

 

I'm no expert but I'd say that cam and those heads would be about 100 horsepower over stock with headers and a good tune of course

 

easy 30 to 40. i would say alot more.

 

Any dyno's around with these heads and similar high lift low duration cams on an LQ4?

If I could 330-340 to the wheels that would probably be worth it. I do Have the 4l80e and 285/75/16's which steal a lot of HP.

 

Any body run a cam only setup and add these heads afterwards?

 

The thing with heads, and other mods that tend to increase airflow is that they add more power as the engines demand for air increases... In other words they add more power with RPM. They generally do a good job of increasing across the board, but you see the largest gains up top. You have a small cam in there. What are your shift points set to? I think the cam will limit the gains you see from the heads. Step up to something similar to what I have (not drastically different by any means) that calls for a higher shift point and I think the heads would be worth more power.

That said, an increase of 30-40 HP is very reasonable and I think you can expect that all day long.

 

Realistacly, I won't be going any higher then factory shift points. I probably won't take it above 5k often, so I'm not sure if these heads will do much over factory 317's in the 2-4k rpm range where I will spend 95% of my driving time.

If the real gain of power from these heads is from 4-6k rpm, then they might not be for me.

 

I think it would be a better idea to just give your 317s a performance valve job and a mill to bump compression. New lifters, springs, and pushrods are recommended with the cam swap anyways.

 

Thanks,
I do have the PRC dual springs and new rods with the Cam package i purchased, I was not aware that new lifters were required for the cam swap. Are the lifters a "must" with a cam swap or just nice to have?

 

you only have to replace flat tappet lifters not rollers.