Ron - There are still some shops that can work on the 261. Best thing to do is look in the phone book and call around. If we know where you are there might be another bolter in your area that knows of a good shop nearby.
Tony's right on the crank and heads. The 848 is the preferred head. If you have checked yet, go to
http://www.inliners.org and check the casting number on your block. Should be just above or behind the starter. I don't know if that's the 717 number you're referring to, but it doesn't hurt to be sure you have a 261 block.
Another suggestion is to get a factory repair manual that includes the 261, if you haven't already. Lots of good info in them.
Good luck.
