I am currently gearing up to built a 92" Hurricane, and getting all the necesary h'ware etc together is starting to hurt the hip pocket lol. I had a 74" P-47 with a ST-3000 and retracts etc and regularly flew her of grass strips with no issues whatsoever. war birds tend to have bigger wheels than aerobatics and retracts are as strong as any other system as long as fitted correctly. I always use hardwood subspars and ply ribs where the retracts are fitted and have never had any problem with them. My hurricane will have a 3 piece wing, the centre section carrying the retracts. It will be powered with my trusty ST-6000 twin, which I am currently having fun making up a new exhaust for to utilise the scale like exhaust stacks as per plans. I'd say the only thing to watch with warbirds is the are a little trickier at low speeds, but just keep a few revs on her and landings are a breeze.