i just gave my 69 r/t the alum foil test. this car has the original carb, intake, air cleaner assembly. also the original motor mount brackets and isolaters so there may be some sag. looks like i might be close to 1/2" from hood/ramcharger assembly. i would think that some clearance would have to be figured in due to engine movement. 1/2" clearance seems to work good with what i have but i'd suspect 1/4" clearance would probably be a minimum.
My friend that I built a 383 for has an alum dual plane on his 383 , I think it's a Weiand ??, with the 383 spec oval air cleaner and I noticed a little rub mark on the top of the air claner , he has no air grabber assembly in it . I looked at the hood and I couldn't really see a mark but he did have a hood pad on it at one point?. Anyway he has a Holley on it and is running a 1/2" carb spacer under it, which I didn't remember being there when I worked on it last year, and with the hood closed I was able to flex the metal slightly with my hand and feel it hit the top of the air cleaner ...
That is way to close, car is a 4 speed and if it breaks a mount the air cleaner is going to hit the hood.
