This might help; maybe not.
I have an old thread in here, I'm going to did up in the AM.
1970 340 10.25, unknown cam and engine to me, even though the wife daily drove it for years- been on jackstands since 1987. It fired up; needs 30 degrees initial to stay running.
Pulled it down, degreed the cam. 230@.050; 274, or 280 lift. C/L 108.
780 carb, rich.even with holes drilled in primarys. Needed 2000 rpm just to keep it running. Vaccum 6 to 7.
Installed a 4.5 valve- a little better, still sucked.
Installed a 3000 converter, and tried it today. It will idle at 8-9 rpm.
with 9 vac at 20 degrees, 14 at 30 degrees, and wants that 30. Go figure.
But I used to run these cams on the street, back in the 70's, with good gas, and they rocked. But was with higher compression.