Where is the location of the timing tab on your timing chain cover? Are you using a stock 8" balancer? Another thing the 305 cid chevy timing chain cover has the pointer at the 12:00 position. Can you get the casting number off the passenger side back of the block? There should be a number on the pad behind the alternator too. Small block casting date is located on driver side rear of block on flange forward of bellhousing. Once you know the date you know the position of the timing pointer or balancer. You can then find TDC. Don't forget to read this link from post #7. Great for timing engines.
http://www.crankshaftcoalition.com/w...nition_advance. Here is another article on the different balancers and timing chain cover pointer location.
http://www.crankshaftcoalition.com/w..._TDC_lines_SBC