Your best bet is 23mm adapters wrapped in some aluminum tape to take up the .5mm on each side of the hex. Any adapter made for a 1/8 scale truck with an 8mm stub axle like a LST, Cen GST, would work on your truggy. Although you might have to add shims between the hex adapter and the outer bearing of the stub axle, if the drive pin is in a different position or the adapter thickness is different. Minor stuff though.
If I'm not mistaken there is someone making 17mm to 23 or 24mm adapters, I think its Integy. But I would rather not stack hex adapters, more things to go wrong.
http://www.rc-monster.com/forum/show...light=d8t+baja
The link of above is the thread that Simplechamp mentioned. He stretched his d8t to Baja length though. Personally, I think you're on the right track not going to full Baja length. It makes the truck too long and narrow. But thats my opinion. Keep us posted on your progress.