Alvin, I've got at least three ways to position the holes accurately, just like I've got several ways to drill and tap the snout of a crankshaft. As always, I'm thinking of the guys who don't have a full machine shop at their disposal. Making simple little jigs to avoid ruining an expensive part is just as much fun as using several thousand dollars' worth of machinery to do the same job. I'm not quite as much of a snob as some of the guys with all the toys!
I wonder what happens to all those original 261 heads that the people discard when they're searching for an 848 to modify? It's a very simple procedure to mill the head down to the same combustion chamber volume as an 848, and correct the valve position and rocker arm geometry. Ditto for the pre-848 passenger car and truck heads!
Jerry
