If you fly the Estes altimeter, be sure to have generous static ports in the payload section. The Estes unit seems to need a faster decrease in pressure to detect a launch than many other altimeters. If you get a reading, it will likely be pretty good. But I've had more than a few flights that came back with the altimeter still reading zero.
The Jolly Logic units (all three of them) are far less fussy.
I did a 1340 from an Eliminator as well. Neat model. So far it's only flown on 24mm motors (via the Estes adapter). I need to go over to the the other side of the state to fly it on a 29mm E or F. Maybe this year.
NAR 89040 L1