i have a 351w in an sn95 and i stroked it to a 393. i bought world products windsor sr heads that were 64cc new, but they have been milled to 61cc's. i have a lunati hydraulic cam (.496 in .520 ex lift, duration at .050 tappet lift is 224 in 234 ex) i have the lunati hydaulic lifters as well with 1.6 roller rockers. does anyone know what length pushrod i need to use? thanks guys. oh and its a 74 block by the way.