Yes, vertical on the Accel super coil, got a reply back from them....

"Your request (#9830) has been deemed solved.
Scott, Mar 20 09:29 (EDT):
Hello,

We recommend installing and mounting the 140001 coil vertically. Mounting this coil in any other position could cause a "dry spot" on the coil windings that prevents proper cooling of the coil.

Please let us know if you need additional help.

Thank you,
-Scott"