Are you going with an air cooled VW based engine or a Subaru water cooled engine?. I have owned Speedsters powered by both and my vote is Suby power all the way. No worries about over heating and you get almost 100% dependability. An actual turn the key and drive experience. You also get triple the HP and torque as compared to most VW Type 1 drivetrains. If you plan on driving your Speedster a considerable amount then this an option to seriously consider. If I am not mistaken Carey has said that the majority of their new builds are currently Suby powered. Congrats on your new Speedster build. Have fun during the process and keep us informed as to your choices and progress.