Weren't all 273 engines before '67 solid lifter?
.. this appears true, even through 1967.
According to the book 'Chrysler Engines 1922-1998' by Willem L. Weertman (former Chief Engineer-Engine Engineering, Engineering Division, Chrysler Corporation, Feb 2006):
"In a cost-reduction move, the crankshaft material of both the the 273-cu-in LA and the 318-cu-in LA engines was changed from forged steel to nodular cast iron in 1967. For quality improvement and more consistent emission control, the tappets of the 318-cu-in LA engine were upgraded from mechanical to hydraulic during the same year, with the same change being made to the 273-cu-in a year later. For use with the hydraulic tappet, the valve rocker arms were changed from malleable iron castings, to steel stampings, similar in concept to the rocker arms used on the LB and RB big block engines."
Fun stuff.
- Art
