[quote=B1MAXX].500 down is from TDC not deck.... we are figuring bdc and tdc volumes. why would you use the deck to measure from? [/quote

i guess i coulda measured it .475 down but to me it was easier to account for the postive deck after.ive never had to use this method before i usually have piston specs so im alittle green on the topic but i get what your saying.i guess i get where all the confusion was coming from ......