340dartley
Well-Known Member
- Joined
- Feb 4, 2007
- Messages
- 519
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- 170
I don’t have any flow numbers for either head but I do have a bit of real world experience using the 920s on differnt engines. I had a 273 2bbl motor that I rebuilt with standard low compression pistons back in the early 90s. I had a set of 920s on it with a .488 lift crower solid cam and an edelbrock LD4B. I ran it at the loca drag strip and it ran 15.60s. I built a .030 over 340 for my Dart and before I got heads for it, the 273 let go. (I regularly shifted at 7000.). I used the same cam in the 340 and installed the same 920 heads. The car ran really well with the small valve closed chamber head. I wound up back at the drag strip and ran 13.7 at 103 mph. I eventually did get a set of J heads and with the bigger valves and open combustion chambers, the car ran 13.98 at 102. This was all with a stock AFB carburetor and stock stall 904 trans. My point is there is some power potential in the heads and flow numbers don’t always mean everything. My theory was that increase in compression was more important than bigger flow numbers until you spin the motor past 5000. High rpm you will definitely need the flow.