Quote:
Originally Posted by Judge273
I thought special order axle on RAIII begat a 3:90...special order on RAIV begat a 4:33? How is this verified on documentation?
Cool Judge BTW!
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Great question.
In 68 the axle ratio is found in box 37 of the BHC (S=4.33).
By 1970 the format changed for the dealer invoice copy and that info doesn't appear to be included with any of the documents provided by PHS. It is listed on the Broadcast Sheet though, so if the OP is lucky enough to discover that in his car then he can check box 29 where "XM" should be listed (or XK if 3.90) The Broadcast sheet also has the options listed with their codes about half way down the sheet. GU9 is 4.33 and GU8 is 3.90. From what I can tell 3.90 and 4.33 are the only two special order axle choices for the Ram Air III engine.
If the engine was a RA IV, then the codes would be academic since the only special order axle ratio choice is 4.33 so the only documentation required to validate would be the 362 AXL-SP-ORD found on the invoice copy.
For the subject car....we know it came with a 3.90 or 4.33. The axle code stamped on the axle tube is XM and the julian date code is 259 (Sept 16th). The invoice date is 11/4/69 (308 julian date) so the axle predates the car by 49 days. That would seem to be in the correct range IMO. (For sake of comparison.....my 4.33 axle, which I believe to be original to the car is 39 days before the invoice date). So, the 4.33 axle in this '70 Judge is not incorrect based on what we know at this time.
Someday, if the OP happens to pull the cover and peek inside, there should be some stamps on the ring gear. 39 9 for the ratio.....GM something and then the year code. Here is a photo of what the stamps look like on my ring gear.