I wouldn't cut on the BUB baffles. I think someone said they are $35 or so to replace them. I was talking about the $10 "beer can" baffles. There are triangle shaped tabs folded into the center of the baffle for back pressure. If you really want it to flow, bend them out past the baffle tube and cut them off. You can kinda see them in this picture:
As for mounting them, I don't like drilling holes in my pipes. If you look at the screw set in the pic, I flip that over and weld the nut to the baffle. Then I put the screw inside the baffle so the screw end tightens against the inside of the header wall.
If you want to try this and you do not have a welder handy, have the people ship them to me and I'll weld them up for you and ship them to you.
P.S. I'm happy to help you. I've been the recipient of so much from this site, I'm glad to contribute when I can.
