Henderson 4 engine serial numbers

[MMasa]

I need help determining the year of a henderson engine I have. The numbers on the boss are 23277 (note that the first 2 is smaller than the rest of the numbers so it could be 3277) I also need sources for parts and services for engine rebuilding and repair.
Thanks
Mark

[Perry Ruiter]

In the seventies (?) Ballak put out a list correlating serial to year. I'm not sure how accurate it is, but it is what is typically referenced. You can find it online here:
http://www.hendersonkj.com/ffo/ballak/index.html
The same site has an exchange/forum section (much like this one):
http://www.hendersonkj.com/kjex/index.html
where you can post looking for parts or services ... Perry