moderate Z28

Is it worth it to match your header gaskets to the headers or is it a waste of time?

ss.slp.ls1

iTrader: (36)

It's always worth it to make sure that your heads, intake, and headers are port matched. The unobstructed air flow is worth a couple of ponies. I have never done it though.

moderate Z28

I got the Percys gaskets and there very close. Only certain spots could be a little bigger. I wonder if my Dremel will do it?

ElkySS

iTrader: (6)

i wouldnt bother with it. too many things to screw up with porting heads. not so much exhaust but still

RamAir95TA

iTrader: (2)

As long as the gasket and header flange are marginally larger than the exhaust port (no lip obstruction) it's fine. Matching them won't net much performance.

1989GTA

I would try to make sure the gasket and or header is not obstructing the exhaust port on the head. If the gasket is hanging into the exhaust port I would trim it back.

James Montigny

iTrader: (13)

The gasket should not hang into the passage, but having the header and gasket
larger than the head export interface is actually good for preventing reversion.
Artifically enlarging the exhaust port on a head isn't going to help you any.

SprayedLT1

iTrader: (8)

And just for those who don't know what "reversion" is, it's when the exhaust pulse travels back up the exhaust/header and back into the head, killing scavenging. If the header flange is larger than the port, it's like the pulse hits a "wall" when it gets back to the port.

ss.slp.ls1

iTrader: (36)

I knew what reversion was already, but I didn't know that having a header and gasket larger than the head exhaust port helped prevent it. You never stop learning.