Well I rebuilt my motor prob like 2 months ago and it ran good when i first rebuilt it but had a slight tick which I heard the 350 motors have. Well i was using 87 when i should have been putting in 93 gas due to a error in piston ordering! NOw I have the worst tick ever it sounds like a exhaust leak but i have checked all of that. Im not sure exactly what to doooo. I havnt run a full tank of 93 through it yet. DOes anyone have any suggestions and is it normal after running for maybe 5 min for you to open the dip stick and some smoke come out or the timing gear cover and some smoke come out?