hi i am using the tmc smoke system on a dle-20 where and what size nipple do i drill and tap for thanks

You just want to match it up to the tubing you'll be using, tower recommends this one with that pump
http://www3.towerhobbies.com/cgi-bin...?&I=LXD623&P=M

Tip
If the line melts off being the nipple is too short/close to muffler, solder on a 1" length of brass tubing to the nipple, that help disperse the heat and the tubing doesn't have to be right up tight to the muffler.

good luck

thank you ,lol i have every size but the 8/32 my luck [:@]

use the 10/32, it would work ok I'm sure