8n valve guide fit

(quoted from post at 08:45:56 07/27/16) this is my first 8n rebuild done many small and big block chevys as well as Harleys
my questions:
why only install the seals on the intake valve guides? the kits come with 8 of them
wouldn't the seals on the exhaust guides help with blow by into the crankcase or do they just swell up and seal from the heat?
also the intake guides seem to just slide right in, no metal was removed from the bores with a hone but just brushed clean the exhaust guides are a little bit tighter. I have a lathe & can knurl the OD of the intake guides for a little bit tighter fit but maybe the fit is good & helps the valve seat? or should i take a hone & really clean up the exhaust guide bores better?
any advice appreciated.

Thanks,
Nate

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• [*:9a170c4bc4]The seals are not shaft seals - they are on the guide to block bore[*:9a170c4bc4]They are needed on the intake guides to prevent air leakage INTO the cylinders on the intake stroke[*:9a170c4bc4]They are not needed on the exhaust guides because any leakage is OUT into the exhaust system where it probably belongs. You can put them on if you wish - I believe the factory did.[*:9a170c4bc4]The block bores do not wear - aside from normal block cleaning procedures leave them alone[/list:9a170c4bc4]TOH