Had to replace the timming belt on 3.0 Dodge Caravan. I can't get the marks to align perfect. Crank is set TDC and cam mark correct for #1 but cam #2 (the one that moves when belt tension is adjusted) is about 1/16 in. off. Moving the belt over a cog throws it off even more. I can get #2 correct but then #1 is off about 1/16 in. Do these marks need to be exact ? Is the engine so worn (180,000 mi.) that it doesn't matter ? Also what is the correct tension setting (how much play in belt) ? Thanks.