I have a 98 and am getting ready to install a set of Harland Sharp 1.8 roller rockers that i just bought from a forum member. My question is, would there be any real advantage to changing to LS6 or LS2 heads? I am going to need to replace my valve springs so I'm just pondering some other possible changes while I'm at it.
Any advice or info?

 

How much are you willing to spend? Do you want more horsepower? Heads, cam, and tune (the full power mod) is my recommendation. But it's gonna run $3-$4K.

 

I've already added a Vararam, LS-6 intake, long tube headers with off road pipes and x-pipe, B&B PRT rear exhaust, Vortex power duct air bridge, 25% underdrive pulley and a street driven tune (not on the dyno). I know it sounds crazy but my aim is to make it run as efficiently as possible without changing the cam.
I'm wondering how much difference a set of LS-6 or LS-2 heads (are they similar?) might make over the LS-1 heads.
And to answer the question, of course I want more horsepower, doesn't everybody?

 

just got through doing h/c. I recommend swapping to the LS6 heads. I did and with a mild cam they're worth the money I spent.
Ed

 

If you're going to pull the heads off you might as well do the cam. You're going to have accessories off the car anyway and a mild cam will give you great results with either ported LS1 heads or a nice set of LS6/2 heads.

 

Is there any difference in LS-6 and LS-2 heads?

 

No! They are the same casting.

 

If you swap to late model heads, you'll need valve covers and coil brackets as well since they bolt on the perimeter and not center.. I bought some on ebay from a 6.0L truck engine and they work fine.

 

Aaaaaaaaaaaaactually... Here's an idea!

Call around to some of the usual suspect head shops (heh) and see if they have a set of perimeter bolt high performance heads hanging around they don't want. It's pretty hard to get rid of those these days, but you might be able to get a real deal on some worked 97-98 heads.

Good Luck!

 

I would also add you may need valve cover spacers to clear the rocker arms.

IMO you should also do a mild cam so that it can take advantage of the ability of the stock 243 heads, at least a Z06 cam or a 224 cam. Once your down to the heads, its next to nothing to swap the cam.

Good Luck

 

Harland Sharp sells the rockers as being able to fit underneath the stock valve covers but in the paperwork that came with them it mentions that the older perimeter bolt valve covers will require some clearance work. That was when I first thought I might consider a head swap. Isn't it funny how we rationalize these performance mods? haha!
The way I figure it, the increased lift from the 1.8 rockers will give the stock cam a little more breathing capability so it's almost like installing a "mild" cam and not using the rockers.
Any thoughts?

 

If you can get a set of ls6/2 heads on the cheap ,like 300-400,then it could be worth it. If your going to have to pay 600 or more it's getting iffy ,since you can get some decent performing heads for @ 1k or so these days.
I put them on my car without a cam swap and I am satisfied with the results w/ my baby ls1 cam.
I gained 33 rwhp with the heads/tune and shorty headers,and I'm carb legal too

I was for a budget build, but I am now ready for a cam

 

A cam is the same or less $ with much larger potential gains than heads. Stock heads, even the 853's (early casting LS1) still make good power and are not nearly as much of a restriction as the cam. However, big cams do like better flowing heads (243's, ported 241/243, or aftermarket casting). If you have later casting (centerbolt 241's) I wouldn't imagine you gaining more than ~10-15hp by bolting on stock LS6 (243's) even with a good sized cam. Porting is another story.

Bolting on heads (no tune) = ~15rwhp avg on stock motor.
Tune = ~5-25rwhp
Cam only = ~30-60 rwhp with stock heads depending on the cam
Cam+Heads = 50-120rwhp (with tune)
LT Headers = ~10rwhp
Intake manifold/TB = ~10-20hp if cam or heads have been changed significantly.

Underdrive pulleys, high flow cats/vs no cats, aftermarket catback, plugs, wires, TB porting, X-pipes and CAI's are all small gains and usually don't give huge gains on their own (but work great with other mods). Hopefully vendors and tuners don't flame me for this, just stating what I have seen in my cars and friends C5's, as well as forum posts.

These are numbers I have seen from forum members (LS1 tech and Corvette forum) from various mods. There are always dyno queens that somehow gain 200hp from cam and heads, and then there are people with cam+heads who only gain 30rwhp (usually because they didn't retune the car professionally). People look at the MAX gain from a given mod, add that to another mod, and then expect to put out X hp. It doesn't work that way. If LT headers are good for 25rwhp and a CAI is good for 15rwhp...don't expect another 40hp to the wheels....it just doesn't work like that.

 

I have a set of heads for sale in my thread.

http://forums.corvetteforum.com/show....php?t=1741586

Make me an offer I can't refuse. I can't seem to sell them.

Ryan

 

Tell me a little more about the heads. I'm sending a PM.