What is the name brand of your aluminum heads? Also what is the name brand of your distributor? Here are some of the wiki articles from this website to use for information on finding TDC. http://www.crankshaftcoalition.com/w..._TDC_lines_SBC
. Here is another article to help with tuning the advance curve and timing. http://www.crankshaftcoalition.com/w...EI_distributor
. Be sure to check out wiki for more useful info.