So I decided to swap my header gaskets on my hooker LTs for GM header gaskets PN# 12552469. Anyways, go to put one on the driver side header and notice that the GM gaskets have no bolt holes for the outter most holes that the hooker LTs require.

Below is the best I can draw it on the comp...

GM gasket (note the 2 missing bolt holes): the 0s are the bolt holes
0---port-0--------0-port-port-0--------0-port---0

0-0-port-0--------0-port-port-0--------0-port-0-0
The above is what the hooker header needs

See what I mean, the GM gaskets that I have are missing 2 needed bolt holes........wtf??? do I have the wrong gaskets??

If these are the right gaskets, can I somehow drill 2 more holes in each gasket??

Or, can I get away with just using 4 bolts per header instead of 6??

Please help

 

Buy Felpro PN # MS 9275 B

 

That's funny my old gm gaskets did have the outer holes but for the tpis's I needed the inside holes, so I bought a felpro and ended up haveing to moddify it. Hope it doesn't leak.
-b

 

Quote:
Originally posted by CamaroBoy96Z28
The extra outermost holes in the heads are what the headers use to bolt on. The inside ones are where the stock manifolds bolt on because they're a tad bit shorter in width across the head.



Sorry, but i have to correct you on this...the inner holes, closest to the exhaust port are the ones that the headers go into. The outer holes are the ones for the stock exhaust manifolds.

As for the GM gaskets missing the inner holes, I helped a friend do an install on LT's with those exact gaskets, and we ended up mocking up the headers as if we were going to install them, and marking the hole, then drilling a new hole through the gasket. This won't disrup anything because they are the crush ring gaskets


Can I get away with this??

 

At first I was thinking you meant just holes to hold the gasket in place and didn't see the problem, but Hookers have 2 actual holes at the ends? Never knew that...

 

geez guys, simple answer.
yes u have to drill holes. thats what i did, thats what everyone does. the fel-pro's need to have drilled holes also. as someone said earlier, put the gasket up against the header, mark it, and drill it. be very careful the gaskets don't twist.

 

Or just cut the end off the gaskets. I dont think its very much.

 

Go to autozone they will probably stock the LT1 fel pro performance gasket in the "performance" aisle. One by me has em for like 26 bux? Wont need to drill any holes then.

 

I had to drill holes in my GM header gaskets too but they didnt last long so I got a set of Felpros #1406 and so far they have lasted great.