Chevy 4.3 timing

What should I set the base timing on a Chevy 4.3 using a HEI distributor and quadrajet carb? (No computer) It is in an S10 racing on a dirt track and using 110 octane fuel.

set the number one to TDC then adjust the timing using vacuum, it may be the only way to acheive the best timing without over adjusting
but after that you will need to use a light to make sure it is not too far out of time (clank boom is not a good sound)

Set it to your base timing specs.

True timing seting can be done by moving up timing till you get a spark knock and then bring it back untill no spark knock.

I'd try someting like 18-20 degrees initial and 16-18 degrees centrifugal, 34-36 degrees total timing, if it pings pull it back a tad or richen up the mixture