Got a boat with a 455 in it the kid told me it was built a year or so ago but the motor looked like shit.  Rust oil etc everywhere. Wife pulled the motor down last night.  Bottom end looks good still has cross hatch in cylinders everything looks clean except for carbon on pistons.  Heads are a different story.  Thick black varnish on the intake side.  Looks like a couple of valves weren't seating right.  Guess I'll have a valve job done and the head surfaced since it looked like it leaked water out of the side.  If I have them surfaced will it affect the valve lash since there not adjustable?   They're flat tappet hydraulic.   What else do I need to look for on an Olds motor when putting it together?  Do they make a 1pc pan gasket?

i am nowhere near an expert but i say yes.

Thought you had to have hardened seats to run unleaded fuel?

I have an Olds windage tray with bolts if you want an easy painless way to minimize oil drag on the crank.  $40 + the ride.   

Sweet!  I might hit you up this weekend.  Now every time I look for a gasket kit for it they never come with intake gaskets.  Why are those separate?   Do I have to get a valley pan too?  Sorry for all the ignorance buy I've never messed with an Olds.