Hi,

can i use the stock L03 heads with the ZZ4 cam? I dont know how much Lift can be used with these Heads. And can i run the Engine with the stock Prom until i get the stuff to do my own?

Im going to change the whole Valvetrain, Intake, Headers and 3" Open Exhaust. Ultimate TBI already done.

If i can not use the ZZ4, which is the biggest cam for use with the L03 Heads?


Nebu.

 

Your going to have to change valvesprings.
I dont remeber the spec's off the top of my had but the ZZ4 is around .500. Probably want to go with screw in studs too.

Just get some new heads, L03's blow anyway.

 

If the heads are anything like the 193 heads I have (which are swirl ports like the LO3 heads), they don't have much clearance between the retainer and the valve seal.

.470" is the lift before they hit each other, and allowing .005" of clearance leaves .465" of max lift.

You can find other cams that have similar durations with less lift. You'll have to shop for them. Keep in mind a lot of them aren't going to be roller cams though.

If you do find one that's roller, it's not going to be nearly as cheap as that cam.

 

He hit it on the head. The stock heads can only take .480" lift. That is with aftermarket springs. The ZZ4 cam is a bit big to use on the Lo3 heads. Not only will it be hard to tune but you will not even see the power potential of it because of the crappy heads. Look for low lift high duration with a lot of LSA (112 or higher).

 

Thx for the info. What about a Crane PowerMax 2032 (214/220, .452/.465)? But i can only use 1.5 Rocker with that, am i right?


Nebu.

 

that crane one would likely work , but i am going to ask the tough questions now.

you have THE WORST HEADS GM EVERY MADE on your car. why go through all the trouble without upgrading heads. hell even stock TPI heads, unported would be a much better heads, especialy if you are going for a cam uprade, realisticly any cam upgrade you do will be disapointed, the duration will help a bit, but the heads just don't flow enough to really take advantage of the added lift. now, the ZZ4 head, with some TPI heads, minor port work, and the upgrades for the lift, screw in studs, cut down the valve guids, ect. is likely a 275+ hp 305. that aint bad considering the price of your upgrades, the TPI heads are cheap, you can get them for about $50, add $100 in for machine work, another $100 for misc parts (retainers, locks, studs, ect) and you will be far and away better off than trying to polish the turds on your car now.

 

ok ok. i go with the torquer heads i hope the shipping will not be so high (i live in germany)... they use the same rockers, pushrods and so on like the l03's? do i need new valve springs or are they included with these heads?


Nebu.

 

it depends on where you get the heads from. i am pretty sure everything will move over, the only thing to check is if they are using guidplates, either need new pushrods, and rockers, or you need to take the guideplates off. also i would suggest new rockers, the stockers are called rubber rockers for a reason. most aftermarket springs are good to about .550 lift, so you shouldnt' have to worry there.

 

It's pretty much pointless to put a cam in any bigger than .450 lift because the stock heads simply don't flow any more beyond that.