Goodson is nice stuff.
you only really need two of them with a long 6" shaft for this SBC head porting job.
LFR-34C and LFR-46C
Yes these Double cut style are for cast iron. Not good on alumunum.
Use single cut for aluminum.
There are other sources that are a little less pricey.
But avoid cheap chinese junk.
Welding supply and industrial tool supply stores usually have all this stuff.
google search carbide burr The same onces but with a 3/8" cutting head diameter are about half the price.
I use the various shaped mounted stones to shape the short side radius. The amount of material that needs to be removed is not that much to shape the short side. radius.
You don't need to run these at 10,000 rpm.
Ebay: remember good quality tools are not sold for dirt cheap. Can be real hit and miss.
Last edited by F-BIRD'88; 01-30-2013 at 12:47 PM.