3rd member/R&P questions

e rock

 
Joined
Feb 24, 2004
Messages
1,620
Location
Monroe, WA
My buddy has an 82 pickup and is in the process of swapping diffs.

The one he took out was stock original and had a R&P count of 41/10 for a ratio of 4.1:1

The one he's planning to put in is from an unknown year, but has a tooth count of 37/9 for a 4.11:1 ratio.

The ratio difference is basically negligible, but my question is why the difference? Did the gearing change for a particular model year? Is one stronger than the other? Is there any compelling reason *not* to use the 4.11 diff?

The only info I've been able to find suggests that 7.5" diffs came with 4.10s and 8" diffs came with 4.11s, but I couldn't find any year-specific info. I thought solid axle minitrucks always had 8" diffs??

Thanks,
Eric
 
Joined
Feb 23, 2005
Messages
315
Location
Littleton Colorado
I dont know if it was the diff size or not. My friend Jason has a set of factory 4.88's all set up out of a Toyota. I have heard they are hard to find... Seems like 4.10's were the most common. Myself, dont know if the difference in gear ranges would work. Sorry.

-Perry.
 

KLF

Frame waxer
SILVER Star
 
 
Joined
Apr 5, 2003
Messages
7,813
Location
Southern NH
Enigma said:
I seem to remember that 4.88's came from trucks with the factory automatic tranny..4.10's being manual.
In the 89-95 series, it went like this:

V6, 5-spd, 235 stock tires = 1:4.10
V6, 5-spd, 31" tires = 1:4.56
V6, AT, 31" tires = 1;4.88
 
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