Engine number's

[Russ69Runner]

Hello Guys. This is a number related question on the motor next to oil pan. The number is RM3H96117 then their is like a degree mark after that is 30. Dose this indicate that the motor is bored 30 over. Other number's on motor's with the degree mark usually indicates bored over. Well thought I would ask. Also do casting number's tell me any thing else about the motor. Thanks for all input from my fellow bird lover's.

 

[Big John]

I have no idea what the "30" is, but it does not indicate a .030" oversize piston.

Chrysler never bored the production engines .030", instead the oversize was .020". BTW, I've only ever encountered one oversize engine, and that was a cop car 440.

The marking for oversize pistons was "A".

I'll bet that stamped number is actually RM23H9G117830. Now look at your VIN... Any chance that's the same number?

 

[69hemibeep]

On a 69 it should be a full VIN like John suggested, it might not be yours though.

 

[Russ69Runner]

Thanks John and 69hemibeep. Its kind of got me the motor is not the motor that came with the car so it not a number matching car neater was the transmission someone put an automatic in it. I have a four speed to put back in it that is what it came with had clutch pedal. All the other vin number's are their like radiator support and trunk gutter. Well thanks know the motor was replaced I am the third owner of the car. Ok just was trying to figure why a small 0 then 30 unless someone bored it out and put this after the vin. I won't let it bother me it run's fine and will put it back in the car when done restoring it. Thanks again. Russ.:wave:

 

[droptop]

Some codes that I found on the internet, so they have to be true.

OTHER STAMPINGS:
Diamond = 0.008-in. oversize tappets
Maltese Cross = 0.001-in. undersized crankshaft
Maltese Cross and an X = 0.010 undersized crankshaft
A = 0.020-in. oversized cylinder bore
B = 0.010-in. undersized main and rod bearings
E = cast crankshaft
H = standard 4bbl
HP = high performance
LC = low compression
O.S. = 0.005 oversized valve stems
P = premium fuel recommended
R = regular grade fuel may be used
S = special engine
WT or TW = water test
X = oversized valve guides

ASSEMBLY PLANTS:
K = Toluca
PT = Trenton
M = Mound Road
T = Trenton (400 and 440 only)
MV or MN = Marysville

 

[Ranger]

Why would the factory oversize a cylinder bore? :huh:

 

[droptop]

Why would the factory oversize a cylinder bore? :huh:

There were still imperfections at the standard bore.

 

[Russ69Runner]

Ok Guy's the motor look's like it was gone into. I will know when I open her up and put on all new gasket's will check the bore. Thanks for the input just can't figure out the small 0 then 30 will find out going to mike out the hole motor when the rust monster is at bay. :wave: