All Small Six 1973 + 200 ci 256 degree stock cam

[78_200_C4]

ENGINETECH + MELLING details show a 10 degree cam change from 246 to 256 1972 -1973 on the 200 six.
I currently have the ENGINETECH ES658 in my 78 200. I wanted to run a Comp Cams 260 but I sent it back do to base circle run out. The Comp Cam had the same casting number on the camshaft as the ENGINETECH ES658. The ENGINETECH ES658 has zero base circle run out.
The MELLING FOV9 + ENGINETECH ES658 256 degree camshafts were installed in 250 engines in 1969.

1973 Maverick 200
MELLING FOV9 Specifications
Advertised Exhaust Duration 256
Advertised Intake Duration 256
Exhaust Duration at .050 inch Lift 185
Exhaust Valve Lift (in) .366
Intake Duration at .050 Inch Lift 185
Intake Valve Lift (in) .366
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1972 Maverick 200
MELLING CFC3
Advertised Exhaust Duration 246
Advertised Intake Duration 246
Cam Type Hydraulic
Exhaust Duration at .050 inch Lift 180
Exhaust Valve Lift (in) .350
Intake Duration at .050 Inch Lift 180
Intake Valve Lift (in) .350
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1973 Maverick 200
ENGINETECH ES658
Exhaust Duration 185
Exhaust Duration at .050 inch Lift 185
Exhaust Lobe Centerline 103
Exhaust Valve Lash HYD
Exhaust Valve Lift .244
Exhaust Valve Lift with Factory Rocker Arm Ratio .366
Intake Duration 185
Intake Duration at .050 Inch Lift 185
Intake Lobe Centerline 112
Intake Valve Lash HYD
Intake Valve Lift with Factory Rocker Arm Ratio .366