To advance or Not

Absolutely my experience with the 400 M RRR
Pistons and Head
but look how it did in the Enginemasters build
We tried to build some for propane PITA
ended up using 460s
BTW mopar truck and industrial also used that retarded timing
and our Chrysler autos went through the compression drop stupidity
no vac advance until speed or gear
the 73 400 in the spedo cable rpm switch- A great Find
performance cams used for emissions
70's was a big downhill slide
Made a lot of money rebuilding transit bus motors
That's where the KB piston came from