I used an Engle hydraulic flat-tappet in my 406 SB Duster; 214/224 @ .050, .470/.504 lift IIRC. Car ran great, idled smoothly but sounded stout, pulled plenty of vacuum for the power brakes & A/C, pulled 17MPG, had perfect throttle response, pulled to 6000 or so. It runs a Demonsizzler T-Quad on a Performer intake, cleaned up iron heads, basic headers.