M1 tunnel ram. 6% positive (6K) Mopar Performance P4532067 Tunnel Ram Top Upper Plenum 340 440 Dodge Intake M1 New (Other) 2 product ratings - Mopar Performance P4532067 Tunnel Ram Top Upper Plenum 340 440 Dodge Intake M1 $199. Stock port window, no issues or bad threads. Louis, MO metro area. Has Superformance gaskets between the top and base. A little beveling, welding, smoothing, and it will be ready to go. com. This is the top half only. I think it turned out very well. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Feb 5, 2024 · I did a 65 cubic inch plenum volume reduction on a Mopar M1 Tunnel Ram top to better suit my intended RPM range usage. gone 9. biuprikn qsnzbz ngtm wypn juiud rahnho omopq llrinnj jyyl ysdlr