[Marshall V. Daut]

Consider that the 1932 Model B four-cylinder engine was basically a beefed-up Model A engine. The main differences - aside from a large journal crankshaft that was later counterbalanced - the Model B engine featured a slightly more aggressive camshaft, a larger CFM carburetor with a wider intake manifold and a 4.6:1 cylinder head. That 4.6:1 ratio is only slightly more aggressive than the Model A's 4.2. This engine was rated at 50 horsepower, meaning 10 more than the Model A. That equates to a 25% increase in horsepower. Sound familiar?
The "high compression" cylinder heads being produced today for Model A's and B's are at least 5.0:1. A couple are 6.0 and some even 7.0+. It's not just the compression ratio that makes the extra horsepower. It is also the design of the head's combustion chambers that creates the right turbulence and spark travel that help improve performance. These heads will definitely increase horsepower AND torque. I should think that the 5.0 head might not supply the extra 25% increase (10 HP), but the 6.0 and above heads will give a closer approximation. If the advertised head is one of the heads I described with at least 6.0:1 CR, the horsepower improvement claim is in the ballpark with a little fudge factor allowed.
Marshall