On a trip to portland this weekend my cam decided to give up the ghost. I decided that in the interests of reliability I would replace it with a stock D fuel inj. one. Replaced cam,followers&pushrods,& oil pump. After a 12 hr. thrash on the street in the rain I realized I had changed the cam -dist. relationship but managed to get it running by changing plug wire position𖐬 deg. off]. After adjusting the valves I still had a knock , but a different one. It sounds like a rod bearing knock at idle but goes away if you rev it. 2 observations 1.I had to take up a lot of slack in the adjusters. 2.My mixture went from way rich to lean. I measured the old cam when I got home & got .405 in. gross lift & a 1.120 in. lobe circle. The parts came from IPD so the cam is an Isky. Could the lobe circle be smaller? A rebuild is in the works for next winter, but the house gets finished first so the cash isn't there for it now. Any ideas? Should I not drive it? It hasn't gotten any worse in the drive from portland to chelan-300 mi, but it concerns me . I don't want to do any irreversible damage. Thanks Mike M.