Fitted the wing spars to the carry-thru and reamed the bolt holes. Had a problem with two of the holes and will have to put either an oversize NAS bolt or ream to the next size (allowed to go up to two sizes larger according to Rans). Not happy with myself for being careless in such a critical area. Started assembling the center section floor and side wall framing. Spent a lot of time tracking down NAS bolts. Had to order from airline suppliers with minimum order levels. Ended up with a lot of extra bolts!!