Another 12 bolt question

**KNAPPY** · #1 01-09-2005, 01:50 AM

I have a 12 bolt that is suppose to be for a 66 nova but numbers are wrong. Housing # is 3875745. Date code is I-30-5. The axle code is CW 10 08 B. This is a leafspring type rear. It is about 52 1/2 in. flange to flange. Any ideas???

COPO_Anders · #2 01-09-2005, 01:46 PM

The CW-code is for a Chevelle with 3.31:1 gearset. But the axle tube flange to axle tube flange should be 54 1/4".
I don´t have my -66 Chevy II nearby so I can´t check the casting #, but they are not always by the book.
My -69 SS396 Chevelle has a 3959058 NF casting #, but Alan L. Colvin lists 3894939 as the correct #.

Anders

**KNAPPY** · #3 01-09-2005, 07:25 PM

This is a strange rearend. The guy I bought it from said he took it out of his 66 nova. I looked up the numbers in Colvin's book but could not find 3875745. Date code and axle code match up and it dosn"t look like its been messed with. It dos not have the "ears" that chevelle rearends have. I have another 66 Nova 12 bolt and the housing on that one is # 3894860 like Colvin's book said. Both rearends look the same?

**Mr70** · #4 01-09-2005, 08:01 PM

Are you accurate on those codes & dates you posted??

**KNAPPY** · #5 01-09-2005, 09:36 PM

Positive, I have checked them several times. Has anyone seen that casting number? 3875745

COPO_Anders · #6 01-10-2005, 07:59 PM

The casting # on my Chevy II 12-bolt rearend is 3852980 N. I couldn`t see the casting date, but it was stamped BS0508G. It had a posi 3.31:1 gearset. I guess this is from a -65 ?

Anders

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