Detonation and general abuse are the most likely culprits.
I have proof that #4 cyl has seen detonation over the years.
Flow in the intake is pretty bad on#4.

I`m wanting a bigger cube and less compression like 10.5 or so.


Any opinion on 383 blocks?

70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!