None exist and haven't for a very long time.
Help us here Marc. We're push rod guys so re-grinding an old stick to a smaller base circle but higher lobe lifts can be 'fixed' with longer push rods.
Are you saying that current blanks can't be cut to the 'H' spec because there is not enough material in the rough cast lobe?
I get it that with an OHC setup the cam is running directly on the valve stem - so a blank cam shafts gross lobe diameter is the limit of lift that can be be ground in.
I do nit have any experience with grinding cams out of base circle since I haven't had to do it. My car is a 69 Sprint with the H cam everyone wants. Also, the Pontiac OHC camshaft rides inside an aluminum housing with no bearings. I think the problem is with a timing issue? Not completely sure. But there is a guy that has made from existing cam gears some adjustable gears to change timing. The market for these cars has never been a good one for racing. There are a few out there and heck one guy has a 69 FB Sprint with a blower on it putting out over 410hp. The number of these guys doing it are very very rare and low in numbers. The market is more for the original restoration in 66/67 Tempests and 67-69 Firebirds. The factory Sprints are coveted and go for higher prices. The goal with this run of cams was to provide something that never has been, the "H" cam. Anyone can buy a H cam, take the cam tower off, bump the cam out and replace it and put the cam tower back on and go. Boom you have an extra 20-25 hp from regular Sprints and even more out of the 1bbl cars. I have been talking with an older OHC guy about doing this for these reasons. 1. Keep our OHC's running! 2. Add some performance that everyone can have. 3. Its never been done before. He has mentioned cam blanks and might do it but we need to find out what the market place wants first. So far, as expected, more want the H cam then the blanks. But, that doesn't mean that he won't do it.
