Series 1& 2 Barrel lengths

[martyn dwane]

Im aware that series 1 barrel & piston are shorter ,but are series 2`s also shorter, certainly EIbar 1&2 and very early 3`s are .
If they are different length`s how does a series 1&2 exhaust ( listed as same on most selllers websites ) fit ? Theres quite a bit of height difference.
TIA

[nickw]

I don't know the answer to the exhaust question but I had difference in the length of cylinders when rebuilding my series 2. Didn't make much note of this but did change the head cowling to suit.