Cam Gears

When the rotor button should be pointing when the marks are aligned to 0 degrees crank cam 12 hours

CAM Gear 6 hours? is the number 1 piston is up or the piston is TDC?

Really difficult to answer without more info .... but I'm gonna tell ya there something that will help you on most engines .. Moreover, I assume you are talking about a small block V8 Chevy or Ford ... But anyway here goes .... When the engine is on TDC compression for # 1 cylinder, the timing gear camshaft will mark the 12 hours, a Chevy ... At this point, the rotor should be directed to where # 1 wire is on the distributor cap ... Always make sure that if the son is not in the same situation from the factory, you have enough room for the distributor to move in both directions at least an inch or so ... This way you will have enough room for timing after you make it work ... Even if you had to do on any V-style engine, and it does not run after, just take the distributor back and move 180 degrees of rotor and distributor in the background and it should run. Reason I say this is that some engines run with the timing gear marks pointing to another when you're ready for # 1 cyl to fire and some will be to pull the plug which is 180 degrees around the CAP .. again difficult to answer your question without knowinbg engine especially as you work on .. In all cases, however, the worst thing you can be off is 180 degrees, unless the timing gears were installed incorrectly .. Hope this helps