From: brute4c
Date: Sun May 16, 1999 1:04am
Subject: Serial # decoding
Well, the engine numbers break down like this:
230-----Cubic inch
M-------Military
3-------Year, 1 is
1966, 2 is 67, 3 is 68, 4 is 69
04------Month, in your case April
02------Day, in your case the second day of April
75------Compression ratio, 7.5:1
There could be one or more letters between the Day and Compression ratio as shown below:
S-------Service engine, don't know what that means exactly...
R-------Short block
B-------Oversize bores
A-------Undersize crank and rod bearings