650 barrels on ebay

I think that these barrels are actually a set of late (post -1960) Model 99 barrels that have been converted for 650 use at some time in the past. Which is possibly the reason for the re-lining.

Checkout the attachment. From left to right these are 650...99SS...88. You will note the angle of the top fin. On the Model 99 this matched the old head fin pattern. On the 650 engines the SS cylinder head had its exhaust ports splayed wider and this gave the front fins a sharper angle. The 650 barrel top fin was then curved slightly to match this.

Attachments
650-99-88-barrels-jpg

Which ebay barrels are you looking at?

If they are the ones in the attached ebay ad, they look like 650 barrels to me with the curved front face of the top fin and judging by the thickness of the top spigots they could be on standard so just may need a 1st rebore.

NORTON 650 CYLINDER BARRELS | eBay

They look as though they have been stored at the bottom of a pond. The bottom spigot has been broken - evidence of a previous blow-up? and they have been relined. The previous blow-up hints to me they are 99 barrels.

There are 2 sets on E-Bay . I would not trust either ,I heavily cracked in several places ,the other damaged by rod failure .