chevroletfreak

iTrader: (6)

After another sponsor failed me and has decided to ignore the situation, I am in the unfortunate procress of another build.

It is an LS3 that will be used as a partial daily driver, autobahn runner and occassional nurburgring roadcourse car. It does have the potential to see the dragstrip, IT will be much tougher to do after the last time I will need something that can withstand high revs w/ the 4.56 burnin up the rear and I MUST have something RELIABLE. I cannot afford this build...much less another

The internals are all forged/quality parts. The first decision I am contemplating is whether I need to upgrade to a thickwall, 3/8 pushrod from a Comp Cam pushrod. There is less than $100 price difference so it is not a big deal considering the overall price. However, is it really necessary? I know they will transfer a little more power, but won't they be heavier at a vital point?

The second decision has a much heaftier price tag. Should I go with a Morel link bar lifter over some LS7's? The difference is almost $425! There have not been any problems that I can see from a search with the LS7's, but the link bar has got to be more supportive than a plastic retainer. Again, is weight a consideration also?

So:
-CompCam pushrods or 3/8 MAnton custom thickwall(+$100)
-LS7 lifters or Morel linkbar(+$425)

Stang's Bane

iTrader: (22)

What is your valvetrain combo. Specifically, what springs are you running and how heavy are your valves. FWIW, though unless everything you are tunning is super light, I would recommend the bigger pushrods. Don't worry about p-rod weight. The extra stiffness will more than make up for the weight. Valvetrain wieght on the other side of the rocker is much more important.The pushrod/rocker side is more sensitive to rigidity.

chevroletfreak

iTrader: (6)

Exactly what I am looking for. I have not lightened anything else. I will more than likely be sticking with stock rockers and have already chosen the stock AFR valves with upgraded 8019 springs.

Beaflag VonRathburg

iTrader: (176)

I'm guessing you're still running a hydraulic cam then. You should really design the valve train around your intended RPM range. How high do you plan on revving the engine? What internal parts will you be using?

chevroletfreak

iTrader: (6)

So far I am sticking with hydraulic.

I really don't see the need to continuously run at high revs. It will primarily be a (semi)daily driver. I just need reliability with a touch of power.

Here are the head flow numbers I am working from.

Intake
200....154
300....220
400....268
500....308
550....317
600....323

Exhaust
200....134
300....181
400....222
500....242
600....251

Stang's Bane

iTrader: (22)

If you are running the AFR 225's, which it looks like you are. Go with the heavier p-rod for sure. Those intake valves are notoriously heavy and I think the spring you are running is fairly stiff also. A .120 wall 3/8 pushrod is the best $100 you will spend in that engine.

chevroletfreak

iTrader: (6)

Thanks for the info Stang's Bane. I have already put in that order.

So far, the lifter decision has gone without comment. Does that mean the preference leads to the LS7 lifters over a tie-bar Morel?

Stang's Bane

iTrader: (22)

Honestly, it is a hard call. You should be fine with OEM lifters, but the Morels are a better lifter. I went with the Caddy ones on mine, but looking back and knowing my spring rates now, I wish I would have done the Morels. I don't think I will have any problems, but the peace of mind would have been nice. You have to look at the cost of the insurance vs the rest of your investment. Hard decision to make.

Scoggin Dickey

iTrader: (34)

Good info Stang's.

I will agree on the pushrods, heavier is not going to hurt you as much as a 5/16 pushrod will if it's suffering deflection.

On the lifters, if you are on the fence and worried NOW, then you will never feel comfortable when it's together if you don't upgrade. Sometimes even when someone doesn't NEED an upgrade, it's better to do it anyways because it's never as much fun as it should be when you are worrying about something you might have shortcut on during assembly.

DrkPhx

iTrader: (15)

I had my AFR 225's reworked by Tony and also upgraded to the 8019 spring and lightweight intake valve. I'm running the LS7 lifters and shift at 7000-7200 rpms without a problem. For pushrods, I use the Trickflow hardened pushrods.