What engine oil do you prefer,??.

I use 4 quarts of any good conventional 10W40. To this is added one quart of Lucas racing oil in 20W50. This combination was recommended by Richard Ehrenberg, SAE, the tech editor for Mopar Action magazine. The Lucas oil adds the higher amount of ZDDP without using another additive. It seems to work well in my Commando 273 with a flat-tappet cam-no signs of any kind of wear.