Hi Raf,

I have not seen the firewall of the GP Pitts, so this is just a thought.

If you have less than 1 (one) inch of clearance between the carb inlet and the firewall, you will need to drill a hole in the firewall, so you can get the proper air flow.

My thought is to drill a larger hole to accommodate a portion of the carb inside the firewall, so you can get the proper length when you mount your cowling.

Hope you can get the 50DL into the Pitts, as it will pull it straight up like the space shuttle.
Geppino