Swapped on a pair of AFR165 on my 306 last summer and have had a hard time trying to tune the best out of the enegine. At the time I`m running a Edelbrock 1405 into a old type RPM intake using a 1" four-hole Mr.Gasket plastic spacer. (plastic fantastic)
After reading some stuff about spacers on Ford Muscle I was linked to this utube-video showing some guys diong a intake comparison++. Now I had no way but try this out myself so I decided to cut out the center of my four-in-one to make it into a half-open or 3/4 open type. And it definetly works on my combo. The most interesting part is how this pacer-opening makes the enegine stronger on lower revs. After swapping back to manuel gearing this winter I can`t no longer just fool myself by kicking it down to a lower gear so now I feel the enegines real powcurve much more than I used to. Fine thing, there`ll shure be some tuning this spring.