How is this done on a pair of heads??

Originally posted by gspan1830:
How is this done on a pair of heads?? =
With a plate w/ rubber on one side for a gasket that covers all the holes in the deck that can either be bolted on or held on in a pressure testing fixture & the same on intake inlets or in years past in a fixture with little blocks with rubber gaskets under them to block off the holes.

Then you pressurize the head with about 50-60#'s of air, spray it with soapy water or submerge it in some cases depending on equipment used & look for bubbles. ;)

Thanks Wolfman, it's really nice to have someone in the know in here.
I have another question, how many cc's can be dropped by going to bigger valves?? I know it will depend on how much the old valves have sunk but what about a ballpark or typical figure?
I've been reading up on this and it looks like the bigger valves will help a bunch even if no port work is done because the new bigger valve sits higher on the seat which improves flow along with the bigger size.
I just bought a pair of 781 heads.

i tried to have my block pressure-tested.i got the same answer everywhere...nobody offers it for blocks anymore! :(

Originally posted by bowtie455:
i tried to have my block pressure-tested.i got the same answer everywhere...nobody offers it for blocks anymore! :( =
I do but the drive would be a bitch :D
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gspan,
About the valve question:
Never really attempted to calculate it. I just put the suckers in & measure the result ;)
But it would be the area of the valves in cu cc's if you want to bother to figure it out
Diameter squared times thickness or height times .7854 all in inches times 16.387 to get to cc's

While were on the subject of pressure testing , is it a reliable way to check for damage? The man who's doing my machine work (if he ever gets around to it) doesnt believe in it because he says "it doesnt always show the problems if they exist,you can just visually check it for leaks" , I dont want to argue w/ him but I bought this 454 engine and have no history on it .I would like it checked for piece of mind , is it nessecary?
Mitch