heads and smog?

[InitialZ28]

I'm pretty much done with bolt ons, now it's time to get into
the engine

I know a 224R/114 or the TR224/114 cams, with a good tune,
can pass smog.

What about heads? Do heads have that much of an influence on
the sniffer test.

My ultimate goal would be 400+ rwhp and be sniffer friendly.
I know my car will fail the visual but there are places who aren't
visual 'intensive'.

Leaning towards the 224R.

Which heads should I go for?
It's between the 5.3 or LS6 heads.

I'll probably have this done sometime next year.
For now I'm gonna wait for sales and start collecting the
necessary parts for a H/C swap.

[Trever1T]

I think if you stay with the stock (ish) heads you'll be safe.

[RrCoX22]

normally heads won't have too much of an influence. heads only compliment the flowing action but normally and probably not enough to make for some differences with the sniffer. the cam is your prime concern. the more overlap the more you FAIL! :banghead:

[krazykorean35]

you should be just shy of 400 with the 224r and stock heads (dan dynoed with that setup at 389 i think)

i would get a set of ported 5.3s and the 224r cam. shouldnt have a problem passing with a good tune.

then strap some naws to it and hit 500!!!

[RrCoX22]

forgot to mention that i put down 430rwhp/416rwtq with the tr224/224-112 and partriot ported 243's :thumbsup: on my old '99 Z/28

[Prerun4fun13]

I would say somthing like a Thunder Racing Cheater cam would do well, you will have a stock idle with that cam because of the 117LSA. I have heard that you can get a 228/228 114lsa cam to pass with a good tune. If it was me i would PM Patrick G and Predator Z on LS1 Tech, they are the cam gurus. You can tell them your goals and they will spec you a set up. My choice would be a set of PRC 5.3 heads with a Pat G custom cam.

[InitialZ28]

I would say somthing like a Thunder Racing Cheater cam would do well, you will have a stock idle with that cam because of the 117LSA. I have heard that you can get a 228/228 114lsa cam to pass with a good tune. If it was me i would PM Patrick G and Predator Z on LS1 Tech, they are the cam gurus. You can tell them your goals and they will spec you a set up. My choice would be a set of PRC 5.3 heads with a Pat G custom cam.

I thought about the cheater cam but it would be a waste because
the cheater was designed for cars with stock manifolds.

[Prerun4fun13]

True, then i would deff just talk to Pat G and see what he can do for you. The guy is a genius

[Buck 9449]

Hello and thanks for the invite to this new site. I drive a 99 GMC Sierra with a 5.3. I've done most of what i can do with the engine without getting internal. But now i think i'd like to install new heads. I was hoping one of you could help me out. I've seen LS3 heads on the market and they look like they would boost the power for me but i'm not clear if they are a direct bolt on or not. Or maybe there is a better head out there? Could someone steer me in the right direction please.
Thanks,
Buck

[jermzz]

Heads wont affect smog, it's the overlap on the cam. Your overlap needs to be 0 or - (negative)

A 224 on a 112 or even 114 with a set of trick flow 215's with a good tune and you'll be fine.

[jermzz]

I thought about the cheater cam but it would be a waste because
the cheater was designed for cars with stock manifolds.


As far as I know most of the off shelf cams are ground and designed around everything being stock.

just adds more when you do heads, headers ETC.

your motor is a big air pump. the more air it pumps, the more power you make.

[RrCoX22]

a 228/228-114 can pass with a dead on tune too...