RE: evolution 58gx
Hi!
Sorry! But your MVVS 58cc engine is way way way too much engine for a 84" Spitfire.
The Brian Taylor Spitfire is 84 " and he recommends a 1.50 four stroke.
I have a MVVS 45cc engine in a 86 " Yak-54 and this engine hovers that airplane at under half throttle...