Pistons or heads? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MONTEZ · 07-22-2010, 10:40 PM

As some of you already know, I have a 6.0l/4l80e that is going into my 85. I am getting ready to tear the engine apart (hopefully next week) and go thru it and do some mods while I'm in there.

The plan is to tear it all the way down and have the block dipped in a vat and repaint it. Also while it is apart, I will be changing the 24x reluctor on the crank out with a 58x reluctor so that I can retrofit the engine with VVT. I will then bring the deck height down a few thousandths to make sure it's slick.

I am stuck on whether to invest the money in a set of l92/ls3 heads. The heads will give me about an extra 40-50hp. Or I can stay with my 317 heads and shave them down a few thousands and put a set of forged flat top pistons in and gain about the same amount of power for about 1/3 of the cost of replacing the heads.

I am leaning toward replacing the pistons and having the option to change the heads later.

Either way I am looking to make 500-550hp at the flywheel.

MONTEZ · 07-23-2010, 12:22 PM

No opinions?

glock35ipsc · 07-23-2010, 12:32 PM

Deck the block, swap pistons, and mill the heads for now if that's what your budget allows. Especially if the gains are similar to just swapping heads.

In the mean time, or after it's running, find the exact set of heads you want and spend the time on rebuilding them with good valves and springs. And maybe even turning someone loose on them that knows how to port and can flow test them to squeeze the most out of them, and a cam that works best with the finished heads. I'm a believer in that most of the largest power gains come from the heads.

MONTEZ · 07-23-2010, 12:48 PM

I think if I go that route, I will swap out the heads for a set of MAST heads in the future. The only thing is that's probably gonna put me over 600hp and I dunno if I'll ever utilize that kind of power. To be honest I think 500hp is gonna be more than plenty. But that's what I feel I can get out of the flat tops a cam and spring package and the M90 controller ultizing the VVT.

But I figured the money would be better spent in the bottom end now and opening up the top later.

When all said and done, I'll be around $2k in the engine, and it will be basically new other than having 46k on the crank rods.

But the head are gonna be another $2k not including springs, valves, and rockers.

glock35ipsc · 07-23-2010, 12:53 PM

Much easier to tinker on the top end after everything is in and drivable.

Just curious, what kind of duty/driving will the truck see when it's done?

MONTEZ · 07-23-2010, 12:58 PM

Quote:

Originally Posted by glock35ipsc

Much easier to tinker on the top end after everything is in and drivable.

Just curious, what kind of duty/driving will the truck see when it's done?

It's a fair weather truck really. Just a weekend toy when the weather is nice. I may take it on a few road trips and would like to go on power tour one year. I'll probably let MAST carry it arround to some gatherings if they choose to.

I have an 09 Hyundai ACCENT DD. 41 mpgs!!! So the truck may see 1500-2500 miles a year.

basemodel67 · 07-23-2010, 04:43 PM

Hmmm, I thought 6.0's were all 58x reluctors from factory.

Maybe I'm wrong. Maybe I'm not...

glock35ipsc · 07-23-2010, 05:03 PM

If I remember correctly

, Gen III engines are 24x, Gen IV engines are 58x, except for 05-06 LS2's which are Gen IV engines but use a 24x. Black = 24x, gray = 58x.

glock35ipsc · 07-23-2010, 05:13 PM

Here we go, found my bookmark:

http://www.ls2.com/forums/showthread.php?t=834483

chevydog66 · 07-25-2010, 05:58 PM

I would do the bottom end first and then get some of these later. Dart LS heads. http://www.dartheads.com/products/cy...der-heads.html

07-22-2010, 10:40 PM	#1
MONTEZ Registered User Join Date: May 2010 Location: Nacogdoches,Texas Posts: 330	Pistons or heads? As some of you already know, I have a 6.0l/4l80e that is going into my 85. I am getting ready to tear the engine apart (hopefully next week) and go thru it and do some mods while I'm in there. The plan is to tear it all the way down and have the block dipped in a vat and repaint it. Also while it is apart, I will be changing the 24x reluctor on the crank out with a 58x reluctor so that I can retrofit the engine with VVT. I will then bring the deck height down a few thousandths to make sure it's slick. I am stuck on whether to invest the money in a set of l92/ls3 heads. The heads will give me about an extra 40-50hp. Or I can stay with my 317 heads and shave them down a few thousands and put a set of forged flat top pistons in and gain about the same amount of power for about 1/3 of the cost of replacing the heads. I am leaning toward replacing the pistons and having the option to change the heads later. Either way I am looking to make 500-550hp at the flywheel. __________________ Smoke Tires, not Drugs

07-23-2010, 12:22 PM	#2
MONTEZ Registered User Join Date: May 2010 Location: Nacogdoches,Texas Posts: 330	Re: Pistons or heads? No opinions? __________________ Smoke Tires, not Drugs

07-23-2010, 12:32 PM	#3
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,684	Re: Pistons or heads? Deck the block, swap pistons, and mill the heads for now if that's what your budget allows. Especially if the gains are similar to just swapping heads. In the mean time, or after it's running, find the exact set of heads you want and spend the time on rebuilding them with good valves and springs. And maybe even turning someone loose on them that knows how to port and can flow test them to squeeze the most out of them, and a cam that works best with the finished heads. I'm a believer in that most of the largest power gains come from the heads. __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE

07-23-2010, 12:48 PM	#4
MONTEZ Registered User Join Date: May 2010 Location: Nacogdoches,Texas Posts: 330	Re: Pistons or heads? I think if I go that route, I will swap out the heads for a set of MAST heads in the future. The only thing is that's probably gonna put me over 600hp and I dunno if I'll ever utilize that kind of power. To be honest I think 500hp is gonna be more than plenty. But that's what I feel I can get out of the flat tops a cam and spring package and the M90 controller ultizing the VVT. But I figured the money would be better spent in the bottom end now and opening up the top later. When all said and done, I'll be around $2k in the engine, and it will be basically new other than having 46k on the crank rods. But the head are gonna be another $2k not including springs, valves, and rockers. __________________ Smoke Tires, not Drugs Last edited by MONTEZ; 07-23-2010 at 12:49 PM.

07-23-2010, 12:53 PM	#5
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,684	Re: Pistons or heads? Much easier to tinker on the top end after everything is in and drivable. Just curious, what kind of duty/driving will the truck see when it's done? __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE

07-23-2010, 04:43 PM	#7
basemodel67 Factory Strippers Rule! Join Date: Mar 2009 Location: Shingle Springs, CA Posts: 707	Re: Pistons or heads? Hmmm, I thought 6.0's were all 58x reluctors from factory. Maybe I'm wrong. Maybe I'm not... __________________ "Feast your eyes on a feast of smoke." 67 Chevy Short Fleet PLAN: LQ9, 4L60, D60 Looking for School Bus Gauges - Help me out!

07-23-2010, 05:03 PM	#8
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,684	Re: Pistons or heads? If I remember correctly , Gen III engines are 24x, Gen IV engines are 58x, except for 05-06 LS2's which are Gen IV engines but use a 24x. Black = 24x, gray = 58x. __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE Last edited by glock35ipsc; 07-23-2010 at 05:04 PM.

07-23-2010, 05:13 PM	#9
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,684	Re: Pistons or heads? Here we go, found my bookmark: http://www.ls2.com/forums/showthread.php?t=834483 __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE

07-25-2010, 05:58 PM	#10
chevydog66 GM ONLY BABY!!! Join Date: Oct 2003 Location: Fort Wayne, IN. Posts: 1,998	Re: Pistons or heads? I would do the bottom end first and then get some of these later. Dart LS heads. http://www.dartheads.com/products/cy...der-heads.html __________________ 2 wrongs don't make a right, but 3 lefts do. 66 Chevelle Malibu 406ci, 573hp, 10.99@121mph 96 Chevy Silverado Z71 72 GMC 1500 Super Custom LS 6.0/4L65 on airride http://www.cardomain.com/ride/707879...mc-c-k-pick-up



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