Total timing questions

[Rattiac]

Have any of you done total timing to your rods ?
Recently we did this to my dads camaro (350) . After watching a few vids on this and getting an adjustable timing light. We did this on his car. Even on initial timing (standard timimng on idle) the car did not seem to run right . His motor is just a standard 350 with different heads and roller cam .
I was skeptical because he dosent have a tach yet and we just winged it.
So after doing all this his car runs and idles (purrs) much better. I think after he had 12* of total timing.

Questions;
1.) What exactly is this setting on the gun and why . Some vids say set to 36* but our book said 34*-36*.
2.) Can this be done to any motor ? ( V6 or others)

[Rattiac]

I did find this great bit of info.
http://www.badasscars.com/index.cfm/page/ptype=product/product_id=76/prd76.htm