I haven't gotten there yet but the 90 came out of the T/F Hollywood Zero. It flew that plane with authority and it had alot of extra detail. I had to add quite a bit of eight to the nose to get it to balance. Once I did it flew great. I am planning on glassing this one with 1/2 oz cloth using polyurethane instead of resin. I'm going with the bigger engine to balance out the extra weight.