I have an Evolution 58GX2, which I understand is the same engine as the MVVS 58 Prosport. I also have the Evolution canister and header to go with the engine, but the airplane I'm intending to mount it in has a built in tunnel which will require the canister to be directly behind the head of the engine (mounted inverted). Is there a flex header available to fit this engine and canister, or will something custom be required?