I heard that most of the sixs were such low rev engines it wouldnt be a problem but V8s would be effected, but by the time they were they would be darn near ready for a rebuild anyways. If you hear no pings or knocks go for it!
I recently got a 53 with a 216 and spent about 40$ on gas this last weekend (I just got her road worthy and was a little excited!) running all over town and no pinging and Im not gonna change a thing. -Jeff
