I'd rather go for ball bearing but because of the increase diameter I think the benefit of their additional strength would be outweighed by the extra material I would have to remove from the bulkhead.

A fairly standard 25mm deep roller bearing has an OD of 47mm rather than the needles 33, this would reduce the front end of the bulk head form 13.5 to 6.5. It's give and take, I could stack up 4 or 5 of these narrow section bearings but they're quite pricey.

http://simplybearings.co.uk/shop/p15...duct_info.html

TS3 and I think Drumroll run on needles and do fine.