Alan,
Thanks for restoring my memory. Another weak-link in the 273, that could have easily been corrected. Hour-glass shaped lifters. Yes, good for
increased lubrication, but shaky for racing purposes (above 6000 RPM).
Hard to believe the D-Dart had those units, to go along with stock
push-rods. We bent many a stock pushrods, while utilizing stock valve springs (210 lb. rated w/valve open), and broke (split) numerous lifters.
I just wonder how many guys with the D-Dart ran into valve train component problems with those high-rated tension valve springs.
Bill,
Happy Birthday to a young 71. But don't do it. Stay with the small block, and just try to improve the performance. I still have nightmares of working on the big-block in my Cuda. I wake-up, with (8) spark-plugs looking at me at the end of the bed, singing "Changes" by David Bowie
Paul