i do not think there is any set time frame on the re-build..if i were you just put it on and see how its pulling by simply looking into your catch can and see how much oil etc is in there after a full run.. you can also turn it over by hand and feel it sucking on the vaccum side..if you can feel a slight pull by doing this ..then i would assume you are more then good.......the relief valve has a shim guide on how many inches of vaccum it will pull before bleeding off..i started with 3 shims on my big block and did not cavitate any seals and bearings yet..and not too much excess oil in the catch tank..i purchased my 3 vane used form a guy that used it two (2) straight seasons..
Yes you can run a 4 vane on a wet sump..the only BIG difference between a 3 vane and 4 vane ( performance wise) is the 4 vane will start to pull more vaccum quicker than the 3 vane...you are right...just use one of the relief valves in the valve cover and your good to go...
here is the best place (cheapest) company i have found to buy the pump from...
www.autofabracecars.com
Autofab Race Cars / Arundel Chassis
7443 Washington Blvd.
Elkridge, MD 21075
410-796-8777
Dealer's Web site
GREAT PRICES, RELIABLE FRIENDLY SERVICE..I LOVE JEGS BUT THEY HAMMER JEGS PRICE....their price on a 4 vane is $482.00 compare it to Jegs or Summit..."not even close"
Good luck.. BRIAN