Ryan,RSA Supra said:
It is retard exhaust 3 degrees and advance intake 1 degree not marks. Some cam gears like the HKS mark every 2 degrees, so you would end up out of whack if you move 3 marks.
These setting are what have been found to be most effective on BPU cars, obviously every car with different mod combinations will vary, so dyno tuning would help.
What you said is a common misconception but it is absolutely incorrect. What most people back in the day found to be a good conservative baseline (+1 i / -3 e) is actually indeed measured in MARKS. All the cam gears are marked in single cam degree increments. The confusion exists because the crank is rotating twice as fast as the cam, meaning that 1 cam degree = 2 crank degrees.
I know common cam nomenclature is in crank degrees (i.e. a 272 duration HKS cam means it is "on" for 272 crank degrees, not 272 cam degrees), but when any Supra owner mentions their cam gear settings, out of convenience we always speak in CAM degrees. Cam degrees are exactly what the marks on the cam gear tell you.
When I originally installed my cam gears, I tried +1 marks intake and -3 marks exhaust. (Same as 1 cam degree of intake cam timing advance and 3 cam degrees of exhaust cam timing retard). I then dyno tuned and gained the most power at +1 marks intake and -4.5 marks exhaust, which is how my cam gears are set now.