RE: World models 80 inch p51 engine advice
I made the bushing and got the spinner and hardware together and weighed it, we flew the airplane with out 9oz on the front. Yep, over 1/2 lb on the nose of the airplane. I suspect our CG could have been well more than an inch aft.
Tonight I started playing with the CG of the P-51 on RF5.5 and it didn't start acting like the real one did until it was another 3" aft, and even then I was able to get it on the runway fine. Add some nerves and some wind and there you go.
Now that we have worked out the spinner deal we will get it all mounted up and check it over real good. I suspect the airplane will fly fine once it's got a sane CG.