tailspnr - If you can't get exactly the size you want from DA, here is the website for Aerografix.

http://www.geocities.com/roger_forgu...l?949625721150

Roger Forgues is a modeler and he makes stand off spacers custom sized to order. He will take good care of you. I was very pleased with what he did for me. I cut my firewall to mount the carb inside. My needle valve ended up in the middle of the FW, but only had to make one adjustment on the engine new out of the box. Just didn't see the firewall issue until after I had ordered these. Had a bit more room, but not much for the cowling clearance. I have mine in a Pitts. You will like the DA. DKjens is right on about the engine. Good luck and hope this helps.