Porting BB heads

We disagree here Stroker and I figured there's going to be at least two other members that will argue it...lol.
You started doing the work in '79, and yet you believe better tooling has not been invented in 31 years? Walk around DEI and tell me how many stone valve jobs come out of there. Or Roush, or Force's shop. It's like making the argument that Studebaker had the best points ignition by comparing it to GM HEI. I carry a plug kit in my daily driver's glove box. I make use of it... But ask a good tire shop if plugging is an accepted repair for a radial tire today and they'll say no, it needs an interior patch. Yeah, a plug will seal the air in, but it's not the right way to do it any more and by not patching there are certain risks you(or the guys plugging the tire) assume. By the nature of it's execution and tooling, stones cannot do AS GOOD a job. That's what I said. Lapping does not ensure concentricity... it simply provides the best means to the closest you can get to it. You need to lap in a stone job because that's the step that blends the inaccuracies from the mating surface of the seat and valve. It's bad, so it gets blended. It's the ketchup of the valve job world...lol. A properly done job with a floating head and cutters, does not need lapping. I'm not saying a monkey with the best equipment in the world couldn't screw it up. God knows most Edelbrocks and Indys are a mess so good equipment won't ensure teh perfect job eitehr. But I'll bet a cheesebuger that anything you do with stones and tapered pilots is worse than if you did a set on my guy's Serdi. Not because you suck. But because as good as you can get it, still isnt as good as the top of the line equipment with a guy as good as you are.
I'd be curious to put a runout gage on a stone job with a slightly worn guide... Let's say, .003" clearance stem to guide in the direction of heaviest stress. Then the pilot goes in. Let's say by going 90° to the wear we can get it within 1° of perfectly straight perpendicular to the seat. Now we use the stone for the actual seat angle. You've got at least .001-.002" for clearance of the stone holder and pilot. Adding the possibility of another 2° of rocking, especially when the drive is turned on and off. So we're already at a possiblyworst 3° off perpendicular, and that's at the centerline of the valve stem. At 1" out from that (2.02 valve) you honestly believe you can get a perfect straight and concentric grind with a perfectly dressed stone? How often does the stone get dressed? Because the first grind will be different from the last one if you dress after every touch on the head, but you knew that.
Now compare that to a one pc. straight pilot, with a floating head or table, that will be the same spec as the valve's stem to guide clearance (.0015"), with no additional clearances to take into account, all the angles cut in one plunge into the guide, and no starting or stopping with the cutter touching the head?
I don't care who is doing the work. A better tool means a better job. Period. That was my point.