[Vettezuki]

There's an outside chance the Gods will stop kicking me in the teeth in the coming moths, at least enough to play maybe a tiny bit with the Vette. If I have to pull the engine to investigate and fix the cam knock, might do some other things that I've wanted to do at the same time, namely rockers and lifters. Morel link bar lifters seem the way to go for high value, but what about Rockers? I think I want to keep the stock ratio unless changing will give better higher rev performance without risking passing smog.

[94cobra69ss396]

What are the specs on your cam again? I don't know anything about the LS1 but upping the rocker ratio will give you more lift and a faster opening/closing rate. It could make more power if the heads flow enough to use it but it may also hurt power and RPM potential if the spring rate can't handle it. I've only looked your car over once and I can tell you that your biggest issue right now is your tiny exhaust. You need to address that first.

[Vettezuki]

Cam is 224/224 114LSA .566 lift.

These are just things (at least lifters) I would probably do while the engine is out having the cam knock issue resolved. The rockers could wait.

[94cobra69ss396]

I don't know how good the stock LS lifters are but I have almost 200,000 miles on the stock roller rockers in my '99 Suburban which has the 5.7 Vortec (R motor). Granted they don't see the lift and RPM yours do but still.

For the rockers, if you went from the stock 1.7 to a 1.8 you'd see an increase of .033 for a lift of .599. Do you have the piston-to-valve clearance for that? How about the springs, will that put them coil bind?

[Vettezuki]

Originally Posted by 94cobra69ss396

I don't know how good the stock LS lifters are but I have almost 200,000 miles on the stock roller rockers in my '99 Suburban which has the 5.7 Vortec (R motor). Granted they don't see the lift and RPM yours do but still.

For the rockers, if you went from the stock 1.7 to a 1.8 you'd see an increase of .033 for a lift of .599. Do you have the piston-to-valve clearance for that? How about the springs, will that put them coil bind?

They're not stock springs, but I don't remember what their spring tension is. We would have to measure all these things. Come to think of it, I could also swap the valves. I have a set of the titanium valves. The heads are heavily ported 4.8L truck heads. (Common back in the late 90s early 2000s as a poor man's solution to a little more compression and flow.)

[Shaolin Crane]

Your springs are 165-185# installed and started to bind around.620 IIRC. However the only rockers I would run on an LS are the chromoly magnums and those only come in a stock lift. The valves you have are fine and iI would stick with those, if anything, have some bowl work done to lower your compression.

[C5Natie]

Its been proven the best rockers for LS motors are stockers with upgraded bearings and trunions. Theyre light, strong and handle high rpm. Theres been failures with just about every aftermarket brand of rockers. If you do a search I think youll find a lot of good info. The upgrade trunion kit from Comp Cams is cheap insurance. I made a video on this a while ago.

http://www.compcams.com/WhatsNew/Fil...ionupgrade.pdf

https://www.youtube.com/watch?v=0IoaGBTq2fE

[Vettezuki]

Thanks Nate. What do you think about lifters?

[enkeivette]

Go as big as you can on the lift. I don't think it will have a dramatic effect on smog unlike a change in duration. And any change in duration will be negligible. So its not really pushing more air into the cylinder, just allowing more efficient operation at high rpm. (Stand by for correction.)

Fab up some headers while you're at it. You have 2 hands, a welder, and no excuse. Just jump in balls first, thats the way to do these things.

[enkeivette]

If I were you Id buy some cheap 1 3/4 headers for a regular SB C3, then get some LS flanges, and cut, tweak, and tack to modify.