Pushrod selection

valve height can change based on seat condition. non hardened exhaust valves tend to eat the seats so the valve gets taller under the spring. Slants are the worst at this, but they came with adjustables until well into the 80's. I'd cut and run from the stamped rockers/new custom pushrods/static lifter preload crap shoot right now and get some 273 rockers and correct hydro cam/mech rocker 340TA length pushrods. Then you can give each valve the proper preload it seems to demand nowadays.