The other day I was driving a new project home that sounded great around town but once on the freeway, towards the end of the trip it developed a knock. Oil pressure showed on the gauge but wasn't overly high. I've also noticed a cough in the exhaust on the left bank at idle. I'm guessing maybe bearings and an oil pump?

This was a trade that is basically a freebee and it's a '67 Ford so I'd like to get it running well and trade it off for another GMC.