fast01z28

iTrader: (6)

ok, so with an 01 z28 i have the LS6 intake manifold. i want some GMPP heads and cam, so i was looking at either the ported LS6 heads with the hot cam, or the ported LS2 heads with the LS2 cam. which would be better?

i know that theres better options out there that yield more hp, but i need to pass CA smog and i want the car to still be somewhat driveable.

lsx24

iTrader: (45)

Forget about the Hotcam or the ls2 cam....the Hotcam has too wide of a split duration to pass smog, it will idle lumpy also. There are much better cams out there (see below). The ls2 cam is not much larger than a stock cam, definately not worth swapping.

If you want stock drivability, consider a TR220 114 lsa from Thunder Racing. It idles and drives like stock, will pass smog, and is big enough to notice a noticeable difference in horsepower.

Stepping up to the next larger size, a TR224 114 lsa will also pass smog, and be more hp in the upper end, with a little less tq down low. It should idle close to stock, very stock-like with a raised idle. Both of these are very popular and proven cams.

As far as I know ls2 heads are the same as ls6 heads. They are good heads.

fast01z28

iTrader: (6)

hmmm, i thought the same about the heads, but GMPP offers each of them ported, as different part numbers.

thanks for the info on cams. if i do both heads and cam at the same time i dont need to use the upgraded springs, because the heads should already have those, right?

lsx24

iTrader: (45)

You will have to check which springs come with the heads. Most likely they are the ls6 springs. If they are the ls6 springs, you will need to replace them, because they will not support the lift and profile of aftermarket cams.

You will need to buy springs, retainers, (preferably titanium), pushrods, ported oil pump, to complete the package. Cam install kit (optional) if you are doing the install.

I don't know about the different part numbers on the heads. Do you have a link? Do they come assembled (with springs)? It might be the springs/retainers that are different between them, if they do indeed come assembled.

fast01z28

iTrader: (6)

http://www.gmpartsdirect.com/results...row=6&pkgid=55
second and third ones down.

it looks like they done come assembled. also, the hotcam comes with ls6 springs, which made me think that either of these heads would work as is.

lsx24

iTrader: (45)

Ok, yea those heads come assembled with ls6 springs. So you are going to have to swap out the springs and retainers to run most cams.

The hotcam works with ls6 springs because it has low lift, and easy ramp rates. If you are interested in another cam that will work with those springs, you can try the Comp 216/220 114 lsa. This cam will work with ls6 springs. It will also idle and drive like stock, with a stock-like powerband. It has low lift and slow ramp rates, that's why it can work with ls6 springs. It just won't make as much peak hp as the TR220 or TR224. But it will have an excellent powerband 2k-6k and rev to 6500 rpm. This cam and ls6 heads would make a very nice mild daily driver combo.

The difference in those heads is the valves. The ls6 head comes with the standard Z06 lightweight valves, hollow stem intake valves and sodium filled exhaust valves. That's why they are more. The ls2 heads come with normal valves.

fast01z28

iTrader: (6)

ok cool, thanks. im learning, ever so slowly. lol