cross sills question

[Breadstick]

I found a post that said the cross sills should not be welded in but it didn't specify the year they were talking about. I just started trying to put the wood bed in but the bed strips don't match up (yes, I tried them both ways). I double checked the part numbers and it looks like they sent me the right strips. The previous owner did a great job on the work so far, so this doesn't look like something he would overlook. The cross sills are all welded in and I don't see any holes on the sides where they would be bolted in. Should they be welded in?