This was something we ran across on Cody's Top Swap...the valves were kinda rusted...which was kinda a big yikes on my scale. Kinda a nice bit of info on anyone that Top Swaps...I'd honestly just go get the heads cleaned and rebuilt...hell...even port em if you can afford it. It's worth its weight in gold on a boosted car.
THIS.
Ummm...I did that. It was cool. Then it had no oil pressure...which wasn't very cool. Then I got this new motor...and its awesome.