ORIGINAL: AH1G
I too am building a Super Skybolt, one of the two I have. I'm going to use an OS 120 pumper in it. Note that the plans specify that the thrust washer should be 6 1/16'' from the firewall and should have an isolation mount. I have an OS mount however if used it would place the thrust waser at 5 3/4''. I took a chance and bought a set of wheel pants from Tower for there ARF Skybolt, they are glass, assembled and painted AND they are the same size and shape. Iv'e made a mold for the cowling and have pullled one part from it so far. Man I detest ABS.
I don't think it actually specifies that it HAS to have an isolated mount, does it? As I recall it just shows the 120 with an isolated mount and a 60 2 stroke with a standard one, showing different options. Re: the arf's fibreglass bits, I I emailed GP at one stage asking about the 'glass cowl for their ARF but they couldn't tell me if it'd fit the kit or not. I'm guessing not, since the ARF's significantly different to the kit near the bottom of the firewall.