hello- i bought a desk top dyno to play around with my bbc combo.I was pretty surprisedto see a 54 hp increase changing to a single plane from a dual plane.Do you guys think thats' realistic?

nope.

I'm not sure how much power gain you will get from just that change, but have heard from others that if you put garbage in you get garbage out. You have to be as specific as possible when entering the info. I put my bbc combination in it and it was very close to the hp and tq figures, mostly off only on the rpm range.

i put all my cam and engine info in to it.the only part i'm not sure of is with the heads.bbc heads are wedge style correct?

another option on the heads are rectangular port canted valve and i do have rectangular ports