Ive got the i6 250 in my 78 C10 and I've noticed a small lifter tick, at all times, not just idle. Its a daily driver and I don't have time to replace the valves or lifters this week, I was just wondering if anyone had used Marvel Mystery Oil or any other additives with success as a temporary fix for a lifter tick in the past. Its still only about a 3 week old truck for me, so I have plans in the future, just not right now, so it would really be a temporary fix. Any suggestions as far as additives or adjustments? The oil pressure is at a good level. Thanks!