Doing a 340 for my son's Duster. I have two chain sets. One is a Howard's Cams unit. Sprockets made in USA with a Rolon solid roller chain. Second one is a JP performance, made in Australia. Iwis chain with split rollers. Engine will have a .530 lift hydraulic cam calling for 300lbs open pressure. I've been told I over think things sometime, lol.
