I can do the milling at home,
(Ears perk up) Do tell. How will you mill the heads at home? I've milled this and that including some header flanges on an old Clausing vertical and have always wondered about doing heads. I haven't tried yet partly because I doubt my setup skills. I haven't invested in a proper tramming tool for one thing. And realistically haven't actually had the need. Yet.
To start with I have a good sized sajo mill. Arbor is 40 nmtb, fairly substantial. I have a 2inch face mill shank. Made a 12 inch diameter face mill. Single pt. Is all you need, slow as hell but no need to align/ grind tool pts identical. Lathe bit in slot, or round bit in drilled reamed hole. Preferably set screws pressure in same direction as the cutting action pressure. Flycutters are easy make. Anyways I have tilting table to accommodate the heads angle.
Tramming? No need for anything special. Just throw indicator on your flycutter, or put a chuck on the mill with indicator arm, whatever you got. I will set lead edge .001 lower or so . Only want to cut with the one edge. Yes in theory this will leave an arc, but only like .0003 depth, I'm sure whatever mill is being used is not going to be that accurate anyways.
Only reason I feel ok to do it on this mill is it's particular construction. The saddle is particularly wide. Like 28 inches. I think there will be no sag as the table traverses, where as say my Bridgeport, the dovetails are maybe only 14 inches wide. (Guess, I am not at my shop, ) Just don't think it would be that stable as it traverses and the weight of the work goes from the left to the right. Not to mention there is no way I feel the r8 spindle would be ridged enough at a 12 inch cut. The Sajo's backgears will allow as slow as 30 rpm.
Please note I am not a machinist. I just like building stuff. I am comfortable with my plan, but with a free pair of gt40 heads. If I had a $2000 pair of heads, I would seek professional help. With my heads, if I am not satisfied with the cut, I can just lap them on my surface plate.
By the way, thank you GypsyR for advice relative to my ds2 . And yes I always over think everything. Lol