Correct I was running the CAT 1.7 which measure out to about 1.65.

Do I need a different spring or just add some shim to increase the pressure? I know you mentioned above about a 1.83-1.84 install height will that be enough?

My race engine (452) has nearly the exact same spring & retainer set-up except with the Mancini sold Harland 1.6 rockers and a Mopar 590 cam, and I spin it about 7,500 with no issues at all, so I am assuming the difference in the cam profile is what I’m not taking into consideration. I guess you should know there is some differences when one calls for a lash of .028/.032 and the other .018/.020.

'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119

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