When installing L98 alluminm heads on a 305, do you just use regular 305 felpro head gaskets or what else is avalible? I read in the GMPP book that you should use a gasket with a stainless steel fire ring with these heads. Is this true? For those who did this swap what did you use?
How much of a problem is the EGR hook up with these heads? I have to have the car emissions tested this year and want to pass. what is the best or easiest way to hook it up and work?
Some of the mods on my car right now are a Hypertech thermomaster chip, MSD coil, ACCEL distributor module, cat back exhaust system, 1.6 ratio rocker arms, and K&N filters.

I am new to this message board and appreciate all the help that is given.

 

Not sure about your gasket question. On the vettes they used a heat riser off the number 8 header tube to get the hot air the EGR requires since the heads in TPI vettes did not have the passages cut. Take a look at a TPI Vette and it's pretty simple. Thats why on Edelbrock aftermarket intakes there is an EGR provision on the back, passenger side as well as centered.

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Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

You MUST use 350 head gaskets when installing these heads on a 305. That's because a 305 gasket with a smaller bore will not seal against the 350 head. Secondly, the reason why you must use a gasket with a stainless steel fire ring is because these rings prevent galvanic action between the aluminum head and cast iron block. This would be true for all aluminum head installations.

I used GM #12557236, but don't recommended these because it's compressed thickness (0.051") will lower compression ratio about 1/2 point. My engine was built for supercharging, therefore this was a good choice for me. You might want to consider GM #10105117 which is also a composition gasket with a compressed thickness of 0.028". This will retain your 9.3 to 1 stock compression ratio.

As I stated in your other post, you can bolt everything back on as though these heads have heat riser passageways. I also go through a yearly emissions check and have absolutely no problems (visually or tailpipe results) in almost three years. And I also have not set any error codes (i.e. Code 32 -- EGR).

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Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
12.57 @ 111 mph.
12.04 @ 114 mph (50-hp nitrous).
http://members.optushome.com/au/downunder1/rides/willie/willie.html

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

[This message has been edited by Willie (edited January 07, 2001).]