installing valve guides?

[gary]

I want to put nylon valve guides on an old reynolds but the threads are different. What sould I do?

[Dan Schultz]

I want to put nylon valve guides on an old reynolds but the threads are different. What sould I do?

Of course, the very best thing to do is get nylon guides with the proper threads. If you know what you need perhaps someone on the board can help you find them.
However, if you can't find the proper size.... If the guide you want to install requires a larger thread you can retap the hole. It it's smaller you can put a little solder in the hole and retap to the smaller size. This is a fairly tedious job and really should be done by a repairman who is also a good machinist. Taps are quite brittle and can be broken very easily.