The Hemi's in the 55's had a real weak bottom end.
First sign of trouble is low oil pressure,before crank lets go.
(Just thought you may like to know)
There are three engines used in the 55 Dodges - the Getaway Six, the Red Ram V8, and the super Red Ram V8. The flathead six displaces 230 cubic inches and is found only in the Coronet six cylinder models. The Red Ram V8 is a polysphere (single rocker shaft) and is used in the Coronet V8 and Royal series as standard equipment. The Super Red Ram V8 displaces 270 cubic inches (like the Red Ram V8) and has hemispherical combustion chambers. This engine has double rocker shafts and old timers call it the "double rocker" instead of the more familiar "Hemi." The Hemi is standard on all Custom Royal series and is optional on all Coronet V8 and Royal series cars. The two V8s share many internal components, and will accept manifolds and other components from the 53 and 54 Dodge Hemi of 241 cubic inch displacement. The six is a flathead and definitely not state-of-the-art for 1955. I have driven both Red Ram and Super Red Ram Dodges and can honestly say that there is a marked difference in performance. The late fifties were a time of inflated horsepower figures, but the 1955 figures were based on engines with accessories and were even a bit conservative. The Super Red Ram could be ordered with the power package (4 barrel, dual exhaust) which puts it way out ahead of the Red Ram in terms of power.