Well I've put the engine in factory position in front of an r380 and the top hose which is disco, seems a teeny bit long, but I'm not sure if I've got the rad frame and the front panel slightly too far back. It's literally only about 5-10mm.
The 2 props measure out bang on in terms of working length flange to flange so I'm thinking the engine and box are right (the holes in the mounts are made oval so there's a bit of fore an aft movement to play with).
I've ordered a fender top hose now for the sake of a fiver so we shall see how that fares up.