Cman01

Should the gaskets match the head port or header/manifold port?

LS7 heads have a "D" shape exhaust port. I bought a set of the Hinson headers and the header tubes are round.

So I'm wondering the gasket that I'll use should it be a d shape or round shape gasket?

Gearpuller

Need to use round hole gaskets. I used Fel-Pro part #1440 on my LG 1 7/8 headers and no leaks in 11,000 miles since install and not one loose bolt ether. But my heads had been ported by WCCH which still should not matter. I help a friend a couple of weeks ago replace his LS7 engine with 2" headers and had nothing but the stock steel D shape gaskets to use at the time and they did leak on the bottom of the exhaust port.

jp_tt_awd

I have Texas Speed headers on my car which are round port also. I used the oem LS1/LS6/LS2/LS3/L99/L98 ACDelco 12617944 round port gaskets which they recommend and sell. I have never had a leak, they are mls and superior to most gaskets you get with aftermarket headers.

-jp

erichg1000

I have a set of brand new, unopened, cometic gaskets. I accidentally bought a second set when I purchased my Pfadt tri-y system. Looking around these go for around $49 new? I'll sell them for $25 shipped. Email me at supraboarder530@gmail.com

If anyone is interested in them, email me I will make sure to send the part number and pics to your email. They are the round hole.

BOTTLE FEDvette

Used stock GM gasket. Round port.

GubuZ06

Is this still the correct p/n for the LS7 Z06 with round port aftermarket header? Amazon seems to think this part will not fit the LS7 platform. Thanks!

Ben

American Heritage

As long as the gasket you use (round or D) seals the header to the head (no leaks) then your good to go. Most headers use the round gaskets to seal but there are a few out there that use a D shape.

We prefer to use GM MLS exhaust gaskets. When installed correctly they do not leak. There are some trick gaskets for those "odd" installations.

jp_tt_awd

Yes, it says they wont fit because these are the oem gaskets for LS1/LS6/LS2/LS3/L99/L98 engines not the LS7. The oem LS7 gaskets are d-port not round port. But if you are using round port headers on a LS7 you want to use these round port LS1/LS6/LS2/LS3/L99/L98 p/n 12617944 MLS gaskets. All LS based engines have the same exhaust manifold bolt pattern.

-jp

96GS#007

L98 is a Gen 1 small block. No way those gaskets will work on there.

I do agree they will work fine on the LS7 and are a great recommendation

rio95

I'm pretty sure I reused my stock gaskets with my 1 7/8 ARH headers and haven't had any problems. Some of these comments have me wondering if that was the right decision though.

jp_tt_awd

As we all know GM loves to re use engine designations. The modern L98 is actually a Holden engine, LS2 block with L92 heads. Yes I too remember the old L98 TPI motor.

-jp

96GS#007

Learn something new everyday!

flyby763

That was ok to do. Nothing wrong with it