old erson cam specs 1m286y ?

There's a 420306 but it would be too big for a 273.

• Hi-Flow AM
• E420306
• RPM Range 3500-6500
• Advertised Duration 286°/294°
• Duration @ .050 Lift 242/246 deg int/exh
• Valve Lift .510in int/exh w/1.5 rocker
• Lobe Separation 108 deg
• Advance 0 deg
• Valve Lash .018/.018"
• Complete with Lifters and Assembly Lube
• We recommend Pro-Duty Hardened lifters with .012 lube hole in bottom - Part# ML752 SEE BELOW