engine trouble, oil pressure diving

Hoping for some suggestions and I appreciate it. My 360 engine (stock compression but lumpy cam, stock 360 heads with double springs, edelbrock intake and 800 thermoquat carb) started ticking and would go away and return at times and now pretty much constant after warm up, now including spike drops in oil pressure. Oil pressure would previously be 40-60 when cruising and is now 20-25 with random spikes down to 5 or even 0 for a sec.
The engine was rebuilt in 2012 and has 30-35k on it.

Thanks for your help!
Doug