LCDR

Whats up everyone Im here from ls1tech. I figured/was told this would be a better place for this. So i bought a one owner 2007 eclb 2500hd classic for $1200. Truck had a spun rod bearing so i yanked the engine out. The "lq4" had gen iv rods and ly6 pistons. From what i gather the pistons have a CC of -6.7 and regular lq4 are the same or -6.4. someone correct me if this is incorrect. Truck is going to be my DD/tow rig so its not going to be a ***** to the wall build. im reusing the 317 heads (ported) and maybe a 212/218 cam. I have a black bear ecu on my work truck that ill switch over. So my real question is...is it worth it to get a set of flattops? Motor is already torn apart and on the stand and i can pick up a new set for $169. But will it really matter in the grand scheme of things? does one point of compression matter?And yes i did search but the threads i looked at didnt really satisfy me

FFDP

iTrader: (2)

Maybe, maybe not. Kinda depends who you ask if it really matters.

I'd slap the stock pistons right back in with the head work and call it there but that's just me. Regardless it will make more power and require a custom tune specific to those mods anyway.

I suggest you look into larger fuel injectors too. A decent cam/heads will tax the small 25lb/hr injectors.

LCDR

Yes i think they are almost maxed out on a stock lq4. i was thinking some 8.1 marine injectors.

FFDP

iTrader: (2)

Just regular 31lb/hr 8.1 vortec injectors are more reliable. People have a hell of time finding proper/correct data for the 42lb/hr marine style injectors from all the forums I read.

I can pull the 8.1 data from a tune in 5 minutes or less and be on my way. The extra 6lb/hr will be plenty of extra flow on a cam/head 6.0.

LCDR

noted..approx how many hp do you think they could handle? lets say a year from now i throw some LTs on would i have room to grow?

stock48

iTrader: (16)

Id prob leave the cr where it is if it's a heavy truck. If anything maybe go 799/243 heads on those pistons. Stock injectors max quick. I have a high mile lq4 with 799 heads and a 206/218 cam in my 4x4 tahoe. With stock cats and exh, stock air box etc makes 330 whp unlocked in 2nd gear. The stock injectors are at 100% by 5000 rpm and it runs high 14's low 15's on afr ratio up top and it pings with low timing. Needs injectors bad I just have no time to mess with it.. If you have long tubes, and cia etc you will definitely need more injector.

FFDP

iTrader: (2)

Using a random injector calculator, 31lb/hr injectors on pump gas with a 90-95% duty cycle could support ~470-480 crank horsepower. Give or take a little bit to be on the safe side.

You'd have to do more than just a mild cam swap with headers on a 6.0 to need more injector.

LCDR

400whp would probably be my limit. although in the future i may go turbo. Nothing crazy just something small that comes on at like 2500rpm and just gives the motor a little more efficency. but ill cross that bridge when i get there, gotta get the motor back in the truck first.