RE: Goldberg Chipmunk Engine mounting
Here's my Chipmunk with a Saito 100. I don't remember if Iused the stock engine mount or not. However, I do remember using the general hole alignment that came with the kit.
One change that I made was to replace the fireweall with 2 layers of 5 ply birch plywood. Something Ididn't do which I wish I would have was to add hard points for the cowel mounting. My only real negative comment on the entire arrangement of this cowel is that Ihave to take a lot apart to get to the engine, which seemed to be an issue with the Saito 100 until it was broken in.