head issues and how much to cut off the intake.

Joseph24251_200 said

I purchased a set of heads that seemed to have had no machine work done to them. I had them reserface, valve job, and new valves and spring put on. When I got them back from the machine shop I decided to check the cc on the head and found it to be 68-69 most where 69. Appears that theses heads had be cut before I purchased them. Now i'm tryin to figure out how much i need to cut off my intake manifold. Could anyone tell me how to measure how mucht to cut off the intake.

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The intake bolts locating in the centre of the intake manifold holes is a good guide to go by. Do a pre-assembly with the heads bolted in place and the intake set in place with gasket. If the threaded holes in the head are nearer the bottom of the intake holes -you need a thinner gasket or some machining. If the threaded holes are nearer the top - you need a thicker gasket. most intake gaskets are .060" thick
Vector make a .040: thick and I believe SCE make a .030". Machining the intake makes the intake very "engine specific". - thus if need be I have the intake flange of the head machined.

I personally don't think you will have a problem with the 69cc heads. As for the machining of the intake - I've experienced the too wide affect on an Air-gap too.