What is the correct timing advance for a 350 with vortech heads and a MSD electronic ignition?

Thanks

Timing is very dependant on your motor setup/combo but a good starting point would be 15-18 deg btdc initial which is set with motor @ low idle with vacuum adv unkooked/plugged.

Then you should dial in your mech + your 15-18 deg intial to total approx 36-38 deg btdc with vacuum advance still unhooked & plugged.

Then after you get the intial & mechanical advance dialed in you can re-attach your vacuum advance hose/line to the ported carb port (no vacuum @ idle,vacuum comes after off idle) or a full on all the time vacuum port from the carb whih ever works out best for your setup.

Now your close enough to run ok and then you can test further to dial in the best timing curve for your setup.

Note: the intial timing i suggested is for an aftermarket perf cam and not for a bone stock GM cam but i assume your running a perf cam of some kind.

Scott

While 36º-38º is usually near optimum for standard heads, I think Vortec and other fast-burn heads like a max of about 32º total. As I recall, I think GM recommends something like 29º!