I've done my 4.6 pistons by hand as well. Using the stock heads as a template, I notched 1 intake and 1 exhaust valve with a dremel cutting disc on the crowns all the way around so they have teeth on them. Cut up 2 screw drivers and welded them to the valve stems. Insert through head, mount electric drill,.. spin a little. Measure and repeat until you get the desired depth. Use dremel again for a little beveling of the notches. Viola.

And the screwed up thing is that I never used anything but stock PI cams. I never got around to putting aftermarket cams in the damn thing,..

Unfortunately I cant offer any kind of guarantee. Your best bet would be to see John (Tiffany) at All American and get him to notch them for you.

Hurst