i had valve seat inserts installed on a d6 pony engine, i had to find a shop with older equipment as the pony would not fit in the some of the newer valve repair equipment,
Ross, I had inserts put into both my 3J and 5U main engine heads. When I asked the guy about sourcing the inserts, he just said that he gets "generic" of the correct size. Worked for me so I guess your local shop can do the same thing for the pony.