i have a 77 blazer with a 350. The main pulley doesnt have TDC marked on it so when i want to set the timeing (which sucks ass) i cant! Someone said i could do it at home by finding the number one spark plug and doing something. If someone knows how to find TDC, please give me a step by step description on how to do it...and what tools i need. PLease help soo..my trukc is slow and it burns gas. Thanks!