Flathead 6 rebuild help

I have a problem that is holding up the works on my dodge truck engine rebuild.

How do I get the front oil seal out if the chain case cover?

Another thing is I have a NOS cork sump gasket that is a little hard after being in a paper bag for 60 years, so what do I soak it in to soften it up a little?

Also what are your thoughts on making a manifold to run this 230 cui 'beast' on a Holley 4 barrel carb? And what is the highest compression ratio I can go up to with this engine?

Soak the gasket in hot water overnight.

Highest compression was 8:1 on the 1957 and newer car and truck. It had a different combustion chamber shape from the older engines. You can take .060 off your head for higher compression but the newer head is better.

A 4 barrel is way overkill (too big). What carb is best depends what you want to do. A larger single 1 barrel off something like a 1980s Ford 300 cu in truck engine would work. For an early hot rod look, two single 1 barrels, stock size. For something more modern you can buy a Holley/Weber progressive 2 barrel and adapter. They work well and give great driveability and mileage.