I agree with Phil. The 544 is somewhat lighter than the 145 (duh)and the 444/544 once came with a 1.4 (early) and 1.6 to 1961? and the horsepower was somewhere on the 60 range and these cars were a blast to drive. Place a B20 with a little headwork and you're in heaven. I kept my B20 to a little higher performance by using a VV-61 "torquer" cam from Isky and a nice header with exhaust under the axle. I also had the head mildly ported (matching) and did pertronix and electric fuel pump for reliability. I didn't go to too far because I drive it every day and still want to use "pump" (93) gas. I have a rear axle from an automatic 1800ES (3.91) and overdrive so the car likes the highway speeds and doesn't breathe hard until wind resistance steps in because of the large "face" the 544 presents to the direction we are going. If you shave .050-060 off the head ...the combustion chamber is reduced and compression ratio increases to 9.5 - 9.9 from 8.7 (stock B20F) You'll be on the border of high test fuel and could get pinging depending on load and elevation. If you have a friendly machine shop nearby, have the flywheel lightened a little for better throttle response. Be sure to check your rear axle ratio as you build because mine started with a 4.56 and 3 speed and my torque was great but highway was too high RPMs for comfortable cruising. I now drive 300-400 per week in my 544 B20 and look forward to a long highway cruise.