i have a 91 f150 truck with a 302 stock heads with a crane 2021 cam. will 1.7 ratio rockers be a problem with these cam specs.
Basic Operating RPM Range: 1,000-4,000 RPM
Intake Duration at 050 inch Lift: 190
Exhaust Duration at 050 inch Lift: 198
Duration at 050 inch Lift: 190 int./198 exh.
Advertised Intake Duration: 252
Advertised Exhaust Duration: 260
Advertised Duration: 252 int./260 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.416 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.432 in.
Valve Lift with Factory Rocker Arm Ratio: 0.416 int./0.432 exh. lift
Lobe Separation (degrees): 109
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in. .thanks in advanced

 

My guess is you will be fine, but why don't you try calling Crane? They made your cam and they should know.