Correct length pushrods does help - and don't be surprised if you end up with the roller tip on the outer 3 rd. But, typically, applying mid lift measuring ends up using longer pushrods, not shorter. Have you checked clearance at the retainer, stud and guide plates?
Joe, no contact anywhere..
Things I've changed.
1.Lifters. First tried Comp 854-16's and these wouldn't stay pumped up and had float issues. Pulled them out and put in Morels.
2. Cam. Went from a Extreme Energy lobe to a Magnum lobe (less lobe intensity). Slight improvement, not much.
3. Rockers. Went from Comp Ultra Pro Magnums to Scorpion Aluminum bodied rockers.
4. Distributor. Went from stock points style housing to a MSD Pro Billiet with the top oring installed to ensure no oil loss to the pass. side lifters.
5. Rocker Studs. Used the 135 dollar ARP studs so the trunion is riding completly on the stud and not the threads.
6. Double checked the oil pump pickup clearance to pan. Checked out fine.
7. Have tried adusting the valves from 1/2 turn to 1.5 turns. At 1 turn right now.
Car runs awesome but sounds horrible on a cold start or if you let the car cool off for a couple of hours. Once warm the tapping barely becomes acceptable. Not what I was expecting for my "stock appearing" 70 Chevelle SS.