I did this same thing for a friend many years ago. 80s I believe. All it was in the end was the distr. shaft had rounded out and it caused it to slip while turning the pump. So just to make sure, pull the dist. and then note where the shaft is pointing. Pull the shaft and check for wear. Oil pumps are the most lubercated of the parts in the engine and will likely never wear out under normal conditions. Also don't go with a high volume unless a change in the deeper pan is in order. I don't think we dropped the suspension when we pulled the pan. I hope this helps.