I measured the gasket that was on it and measured roughly .040 at the ring, so that put me at about .085 quench?would it matter if those camel humps have been ported at all?
First problem with old heads is they are not original. By the end of my days as an engine builder (before I got really sick) I couldn't find a set of untouched fuelie heads. They had all been cut to increase compression and some where also angle cut so that there were no steam holes by the spark plug (a sure way to get into detonation as the plug will act like a diesel glow plug long before it ignites the fuel as a spark plug). So you have to CC the heads to determine the combustion volume (hopefully they both measure the same).
Porting the heads has no affect on the compression ratio but a valve job certainly does. Every time you do a valve job you remove metal from the floor of the combustion chamber. With old heads they may have had many previous valve jobs, to the point where the valve seats have sunk below the floor of the head. This sinking means you are loosing lift. You could have to subtract 0.030" to 0.070" of an inch from your gross valve lift no mater what cam you choose.
The other issue with old heads is valve guide wear. If the guides are worn then the valve can not be held concentric to the seat. Therefore the valve will not seal as well as it should. Additionally with worn guides you get oil flowing down the valve stem into the chamber. This is a not only embarrassing in having a smoker; but oil in the combustion chamber lowers your octane rating on what ever fuel you put into the engine (why racers such as myself use a Moroso oil/air separator to prevent the oil from blow-by from getting into the intake and causing detonation).
Finally depending upon the year of the head the valves differed in size which means the valve spring diameter changed with size. There were two sizes of valve spring diameter on the SBC (three if you include the BBC springs used on aftermarket heads). The valve spring pocket may have been cut sometime in the past to accept a stiffer spring or a taller spring that could put you in a canoe (to quote Monty Python in their Socrates sketch) which is "F**king close to water".
This is also a problem with amateur head porting jobs. They don't have sonic checkers or years of experience in porting heads and some of the metal that has been removed could also turn your head into a canoe. A consideration a street head that sees a lot of heat cycles.
Turning from head issues to the block. Chevy usually put the piston deck down in the hole about 0.025" plus or minus 0.010". So there is a wide range in deck height. Without measuring your motor with a caliper you have no idea where your pistons are sitting. There is also a problem of the block warping just like the head does from heat cycling. So there can be (0.015 to
Older engines had piston domes if they were high compression engines that required "high test" back in the sixties. High octane gas is no longer available at the gas pump any more. Today's best is 93 octane, but most states have a best of only 91 octane. Considering that back in 1966 through 1972 regular gas was 89 to 92 octane and high test was 100 to 104 octane. So if you have a high compression engine (11.0:1 or more) then the factory expected you to burn 100 octane gas. Today that is aviation fuel (why it still exists at the gas pump at the airport flight line is because all of the engines built back in the sixties are still running in old Piper, Cessna, Beechcraft's general aviation aircraft still exists.
Today we don't use domes if it can be avoided as the dome obstructs the flame front's path. This results in incomplete combustion, or detonation if the dome prevents the spark from seeing the back side of the dome. Today pistons are flat topped or dished, and we use a smaller combustion chamber to increase static compression.