I've put decomp plates in my v6, but all the timing marks are now all to cock because the heads are now spaced out 1.5mm each, how do I go about timing it without verniers?!?

When the belt is lined up with the crank and routed to the left head it's out by 4 teeth, didn't even bother trying to line up the right set of cams!

Help

 

If I line the crank up, route the belt up the left side with the roller loose its 4 teeth out, if I lined the crank up then lined the left cam up with the line on cambelt I don't think there'll be enough adjustment in the rollers to take up the amount of slack there'll be

 

You havent timed it properly, do it again, it cant possibly make it more than a tooth out, as you just pick the next tooth if it has!