I started out with a 125 lyc. moved up to a 150 cont.(or so I thought) couldn't get rid of that one fast enough. Then to a 180, ran great. For whatever reason I had to have an angle valve, so I tore that perfectly good 180 apart and built up a nasty wide deck angle valve 200. Traded that motor for a great running parallel valve O540. Ran it for about a year and the bug hit me again for a change, and man was it a change my 1st car motor ever! But back to the topic, all my lycomings did me nothing but good. Just wish the cont. 150 would have ran better. Nothing against continental though I built my dad a 470J motor and let me tell you it has sent many a 540's packing!