I'm going to be throwing a mildly built 355 in my car for this summer. Came out of a early 70s camaro and I'll be using the stock heads but they will probably get some mild porting done. I've read many posts and seen that 13* advanced is usually what ppl go for. Would this work with my setup? If you need to know more details, ask. What does this do anyway?

 

Setting the total mechanical advance at high rpm is more important than the inital timng. to get maximum performance. Get a dial type advance timing light and set the timing with the vaccuum advance unplugged, to 34-36deg BTC while reving the motor past 3000rpm. make sure you're reving the motor high enough to max out the centrifical advance. Then reconnect the vacuum advance.

You can do this with a normal timng light if you get a crank balancer timing tape ( Mr gasket) that allows you to see where 36degrees is on the balancer.
Once you've set the timing at maximum advance to 34-36deg BTC , you'll likely find the initial timng at idle is 8 to 16 deg BTC. This range is good for most mild built small block motors.