I have a VE rotary injection pump and I think the timing from Frito-Lay is too advanced. On my motor there are two marks on the timing cover and one mark on the pump. The mark on the pump is a 1/4" to the right of the closer mark on timing cover(towards the block advanced). It seems a little loud and clattery and smokes black on accelaration. Should I retard it by a 1/8" which would leave me at 1/8" advanced? What is the typical distance between the timing marks?