How to get dahdi trunks to work with 2.6 beta2

Hi. I just upgraded to asterisk 1.6.0 and so it no longer recognized channels of type zap. Now for my zap extensions, I was able to change the dial string to dahdi, but for the trunks, I saw no way to do this – I eventually made them custom trunks and did the dial string that way, but is there a better, or rather a real way to do this – particularly I would like to not have to have deleted the trunk and remade it.