1972 Demon 340 engine mods
So I left it sit for a day and went back to the beginning. Went thru what happened step by step... Sometimes thinking works better than doing ;-)
I figured out what was the problem!
It was all happening due to almost zero seat pressure due to too short and soft springs that we put on the Edelbrock heads in place of double springs that were on there. We installed springs from J heads. I went to quickly check this theory and I discovered that I could push the valve in by 1/4" with some push on the rocker arm.
I changed back the springs today and magically all works as it should!
Now it pulls 12 inches of vacuum. Gauge needle is steady as a rock. It idles at 850 with really nice pulse for this cam.
It revs like it should and reacts to gas as should. The power is also back.
Now its time to clean this fuel system mess and swap the cam.
Carb tuning with O2 sensor this weekend.
I hope it helps someone some day.
Thank you for helping out.