Just an fyi you can buy the best humps new from gm still. They sell 492s and they are not that much. More than 250 but new is worth a few bucks more in my opinion.
Best to get a good price for these and see if the difference is worth it to have brand new heads as opposed to used heads in unknown condition.
And yes theu should run good maybe not the best and not the top mark fuelie X head that is a 461 or 462 with 2.02 valves i think. Not sure off the top of my heads.