What Years?

[Mick Milakovic]

Hopefully someone can help me with my new projects:  I just picked up two Penton 250's (I think).  Bike #1 has frame# 54-501-80700 and motor# 5406040.  Bike #2 has frame# 550-00434 and motor# 3-5402485.  What years are these bikes?  How can I tell in the future?  Both are currently in enduro trim, but I want to make them vintage MX'ers.  Question #2:  Do these bikes come with different gear ratios, or all the same?  I don't want to have a wide-ratio gear box on an MX course.
In advance, thanks for any help I can get!
Mick Milakovic

 

[Dwight Rudder]

If not mistaken, The first is a 1974 and the second is a 75.
Cher'o,
Dwight

7 time ISDT / E medalist
7 time National Enduro Class Champion.