Setup for 273

Hydraulic cams and lifters require different length pushrods than the original solid lifter pushrods. Let me put it this way, this is what you need: Solid lifter cam (E-4), solid lifters, solid lifter pushrods with the ball/cup ends in the correct length, and adjustable rocker arms. As far as pushrods, they need to be the correct length and the stock ones may or may not work. The replacement solid lifters may be a bit different dimension as far as where the pushrod seat is located. You may have to get a pushrod length checker and order the correct pushrods to work. The later model heads you are using were for hydraulic lifters. To use their rocker arms you would need the hydraulic pushrods, hydraulic lifters, and a hydraulic cam. You should never mix hydraulic cam valve train with solid lifter drive train. I don't even recommend using the solid lifter adjustable rocker arms on hydraulic cams.