Hi all. I am in need of some help deciphering my 1971 CJ5 V6 Dauntless "Engine Production Code". VIN TAG COWL= 8305037 373185 DASH STICKER = MAR 1971 VIN = 8305037 373185 FRAME STAMP= 373185 ***Stuff everyone already knows but putting it up anyway*** VIN 83 = Universal CJ-5 05 = Open Body 0 = Universal 3 = LHD California, Fuel Evap Control 7 = V6-225 With Emission 373185 = Sequential Serial Number My 1 owner CJ5 (owner now deceased) has an "Engine Code Number" stamp of "DUH 002 R" The son does not remember the engine ever being replaced (does not mean it did not happen) D = Domestic Second letter denotes year cast ***cannot find reference to a "U" in any literature*** H = V6-225 9.0 to 1 C.R. (2bbl carb) The three numbers = julian date or in my case the second day of the year No clue what the "R" Stands for in my case ***What I know from researching block stamps for Buick and Jeep*** From below pic in Chilton 1967 = DNH or from "Service Manual Jeep Universal Series" N-1967 From below pic in Chilton 1968 = DPH or from "Service Manual Jeep Universal Series" P-1968 From below pic in Chilton 1969 = DRH or from "Service Manual Jeep Universal Series" R-1969 From below pic in Chilton 1970 = DSH or from "Service Manual Jeep Universal Series" S-1970 From below pic in Chilton 1971 = DHC or from "Service Manual Jeep Universal Series" T-1971 ***does not match*** I found this on Team Buick's Forum "See attached page from the '74 Chilton repair manual Jeep chapter. This shows the 1967-71 Buick/Jeep V6 codes." Any help that anyone on here can give will be very much appreciated in solving this.