How's clearance from the bottom? Any leaks? I have the same car as yours, basically (67 Coronet 318) and cheapo headers would be a fun add-on, but I have the car slightly lowered and the roads around here can be kind of bumpy.

1967 Dodge Coronet Deluxe station wagon

1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s