Hey all, after spending a bunch of time going through dyno charts, track results, and internal reflection in the pursuit of horsepower enlightenment, I have come to the conclusion that I am now even more confused than when I was looking at only a pair of 205s and a tiny cam.

I'm currently stuck between 3 options for my build, and definitely looking for some advice.
Core aspects of my build are:
Stock bottom end LS2 Z51 C6
The car will be autocrossed, road raced, and drag raced, and also a summer daily/road trip car, so highway fuel economy does matter to an extent.
I don't plan on using a big cam and replacing springs halfway through a summer, I just want the most power possible without sacrificing the 600rpm idle.
Budget is a little flexible, but as cheap as possible.

Right now the three frontrunners are:
AFR 205
AFR 230
Stock LS3 heads

The cam will depend on the heads, but I'm really liking the look of Lingenfelter's selection of Comp Cams, for their relatively easy ramp rate and staying within factory spring specs.
For cathedral heads, the intake would be my factory LS2 for now, until either the Dorman LS2 comes back down, or the FAST LSXR when the budget permits. With the LS3 heads, it would be a stock LS3 intake.

Is the LS3 setup going to be the best for the money? It sure seems that way, but I'm worried about what the low rpm will look like going with that much port volume on a 6.0 with a cam. My other concern with this setup is the compression. I would like to aim for around 11.0-11.5 to keep the low rpm power, and it seems like having the heads milled and running thinner gaskets could spell disaster with too high lift. I'm planning on sticking under the .550 mark at 220*, and thinking that should be good, but don't want to find out that doesn't work after getting it disassembled.

Thank you in advance for any insight!

 

Have you checked out Tusky's sticky on engine combos at the top of this section? Well worth a read to develop more of an idea of what you'd like to do with your LS2.

tusky-s-cookbook-all-motor-builds

Cam lift seldom has any effect on Piston to valve clearance. Cam duration has the majority of effect. If keeping nice 600 rpm idle is important, probably won't be considering a many big duration cams with potential P to V issues.

For lots of driving etc a gentle cam lobe can be a big plus easier on valve springs etc. Probably worth a call to Cam Motion to get exactly what meets you cars needs.

 

Mamo has some wicked heads

 

This is true, but I don't believe hand finished, CNC ported aftermarket heads with a custom cam fall into the budget category. Otherwise I would have reached out to him first.

 

What dollar figure have you placed on your “budget” here?

 

Same question as chevelle what’s the budget? We all know AFR 230 heads are not quite budget heads at least imo

 

You best bang for the buck are go be 243 factory castings with some port work and a LARGER intake valve. A 2.04-2.055 intake valve on a 6.0 bore is very potent. The proof is in the pudding. One car (f body) on here is going 9s with 706 casting heads and a 243 headed car running 10s as well. Both cars have a 2.05 intake valve in the head.

 

It's flexible, but around 4-5k all in on parts.

I was thinking that too, but they only seem to be about $800 more than dressed CNC LS3 heads. To get nearly 95% of the flow from 80% of the port volume seems like a really good deal, but the more I think about it the more I'm leaning towards the GMPP LS3 heads. The only thing I'd need would be to have them milled about .030 or .040.

I still worry that the factory ls2 intake would hold the combo back a good bit. And that 1k I'd have to throw down on an intake would go a long way towards better out-of-the-box heads

 

I haven't seen a HP target mentioned here. IF it is 600 or less, stock LS3 heads have you covered. No porting needed or desired. Just give it a good cam.

 

i agree with G Atsma.. either get stock casting ls3 heads and upgrade the springs etc or go to TSP and get a LS3 heads and cam package and get Johnson lifters. Don’t risk getting “LS7” lifters from the Internet. I lost my 6.0 to “LS7 Style OE” lifters. Granted I got them off eBay.. haha 😂

 

Since I'm buying the heads anyway, I see little reason to not spend the extra $400 for the ported heads, since they'll probably be worth 20-30hp.

 

A budget build all depends on what you can do vs what you have to pay for machine work on block, heads and/or rotating assy.
My sons car is also a 3 event car that you are striving for.
I built my sons 408 (LS2 block base) for under $6k, intake to oil pan. Granted I worked in a machine shop at the time and was the bottom end machinist/builder. So All machine work, porting and balancing was done by myself.
It's makes just over 500 rwhp and 482rwtq. It's a fully forged/ balanced, 10.8:1 CR, ported 243s, Fast 102, NW102, and a few of internal upgrades such as billet oil bypass, crank scraper, windage tray, oil pump, etc.
Granted I could have went with a higher CR but it's a basic build that can run on any octane fuel with a matching tune.

 

It sounds like your son is quite lucky lol. I'm just getting the heads and can installed by a shop, but I'm buying the heads from GMPP that are pre-CNCed. All in as I've priced it, I think I'm looking at about 2500 for all parts, before gaskets and such

 

Where you located? Regional forums on here can help you along as well. So many things have changed. Everyone relies on FB and nearly all local forums have disappeared. But there's always guys willing to help locally. Just have to be mindful of who really knows what they're doing vs guys who learned from google, forums or youtube certified. Also, local guys can steer you in the right direction of reputable shops. Also be mindful of those too. One will say a shop is great and other wills not. That's why I use only one machine shop, (the one I worked at), one tuner (Dr Tuneemall) and build my own stuff.
Years ago LS1Tech had created friendships and groups from guys who were damn near neighbors and didn't even know it.

 

IF stock heads provide all the air your engine needs under ALL CONDITIONS, ported heads will add nothing power-wise. Money wasted if this is a budget conscious build.

 

I'm just going to a destination shop that seems to be really reputable. I don't think they're a sponsor here anymore, but they have a good reputation and put up some pretty mean cars. And as much as I would like to do it myself, I have been down that road before, but not enough to be confident and free time is something I just don't have right now. As for machinework, I only need the heads milled off maybe .020 or .030, and I'm pretty confident most shops around me wouldn't be able to muck that up.

 

Easy, send your 243's to TEA and have them do there job and go with either a Lingenfelter GT11 or a Hawk's Motorsport Sleepr Cam(same cam, different lobes, different lift, similar valve events). It'll check all the boxes for what you want to do. Ask me how I know, I have an LS2 also. Intake matters more than the heads, it's the choke point.

 

For budget you can get ls3 heads and an intake with injectors and rails and tb for pretty cheap. At least, you use to be able to.

 

If it was mine;
TSP porting on your 243 heads.
ported FAST intake.
102 TB
cam around 230@.050
put cam in and measure PTV then
mill heads

 

I'd choose the Summit Ghost cam over the old Lingenfelter GT11.