Bigger valves in a 243s'.

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Mar 4, 2018 | 06:53 AM

1998 TransAm

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Bigger valves in a 243s'.

Hey guys. I have a set of 243s that I am getting ported. I was wondering if I could go to bigger valves while I am at it. Intake would be a 2.18, and exhaust would be 1.60. Anyone else run this set up??? Any input would be appreciated. Thanks!

Mar 4, 2018 | 07:14 AM

KCS

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From: Conroe, TX

Quote:

Originally Posted by 1998 TransAm

The valve spacing on the cathedral heads are only about 1.91". Those valve sizes would give you .020" between the valves, which is pretty tight. They might clip each other when the engine is running. 2.165"/1.55" is a lot safer and more common.

You will have to replace the iron seat inserts in the heads as well. Just the intake side though.