i agree in what you both have said, just putting a bigger head on wont make an instant race car. you will need the supporting mods. this is were people can find themselves spending lots of dollars.

Geez guys,a far amount of guesswork and assumptions going on here.Don't any of our other mechanics on here own a burette.
An un molested round port head(all types)holds 25cc of fluid.
An un molested H89 or oval port garden variety head holds 28cc of fluid.
So as you can see,putting an oval port head on a 1200 bottom will loose you compresion without doing major work elsewhere.

sounds about what I measured along time ago. Whats the open style chamber of an A14?? I'm guessing around 32cc ??

I also think a reduction in compression is a bigger loss than the gain you would get with the larger valves.

I measured an open chamber head several years ago and it came within a .5 cc of the closed chamber head [H89] The open chamber head was not a deep as the closed chamber head. I believe the power is made in the closed chamber head due to better squish and swirl characteristics.

I agree