I checked our tech section for factory gear ratios for the H150 diffs in the USA and found every year B310 listed but 1981. I don't have a 1981 manual but my 1980 factory shop manual agrees with our tech section: that the 1980 A15 manual trans cars had the 3.54 to 1 ratio. With this fact in mind, [and thinking '81 must be the same] I went up in the woods and removed a diff from an '81 B310 with and A15 and a five speed trans. But for some reason after all of my hard work, it was a 3:70!

Does anyone have an 1981 factory B310 manual on hand? What were the available ratios for that year please? Was 1980 the only year the 3.54's were available?

Mike

maybe it was a 4 speed b310 that had the 3.54?

Mate, have a look at my most recent post in your other thread.
In these B310 models, check the build plate [if used in the US] before doing the hard yards.
[Link to thread]

blownb310
B310 SERIES
The

That is very helpful. Thank you Longbrow.

I have every shop manual from '74 up through 1980, so I never saw that chart you posted from the 1982 manual. I never knew they mated the 3.54 with an A14. I always thought they only used the 3.54 with the more torquey A15's. Guess I was wrong.

Now, all we are missing is the 1981 manual specs. Does anyone out there have the 1981 book?

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