Late 70's early 80's Cylinder Head identification help.

I have an early 84 250 WR that is the last of the Air Cooled Heads. Metal from a Cracked Liner dented the Combustion Chamber. I could weld it up and machine it but since these Heads don't sell for all that much why not just buy another one. Only problem is I'm not sure what Years are the same Head. At some point the Spark Plug was rolled over to the side to clear the Exhaust that is cutting threw the Frame ( 82 ?). E-bay is all over the board, I see Angle Plug heads being sold as 77's and Straight Plug Heads being sold as 84's. Besides the Angle of the Plug is there anything else different ? Combustion design ?

Cylinder stud spacing is wider on the 82+ primary kick 250s, it's actually the same as the 430.

So are there Heads with the narrow Stud pattern that have the Angled Plug hole ?

I'm not sure, the 78+ engines might have since they have pipes similar to the later bikes but I can't say for sure.

82/84 primary kick A/C 250's had angled spark plug holes. 75-81 250's had straight spark plug hole, 75-79 250's had the narrow stud spacing. 80-84 250's had the wider stud spacing.

Marty

OK, so what I gather is that there is the ;

75-79 Straight Plug narrow Stud Pattern

80-81 Straight Plug wide Stud Pattern

82-84 Angle Plug wide Stud Pattern.

If true there is no such thing as an Angle Plug Head that has the wrong Stud Pattern, and that the only ones easy to mix up are the 79 to 80 switchover to the wider Stud pattern. This should be true for the 250's, I would assume that the open Class bikes follow suit as well. And 125 are a whole different story.

Yes this would also be true for the open class bikes. Except the 79 390 auto started going to the wide stud spacing.

Marty