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chevyfan87 06-03-2008 09:42 PM

gear ratio
 
i was wondering what my truck may have for a gear ratio...it is part 81, part 85, and possibly part 80. has a 305(original from the 85) with the factory 3 spd auto from the 85, also 6 lug axles (possibly from the 80 as the truck was originally 2wd) but the 81 was a 250L6 2wd...just a question...figured you guys would like the chance to think really hard

Walts_restoration 06-04-2008 12:10 AM

Re: gear ratio
 
if it was a half ton corperate 10 bolts, id say 3.08s. both my 86 and my uncles 85 had those, 4x4 blazers. No real way to tell but pop the cover or turn em.

TeamRinaldi 06-04-2008 02:35 AM

Re: gear ratio
 
I agree, you could have anything. My '85 has a 305 and for a little while a longer the three speed, and has 2:73 gears. 3:73's are in a box in the garage patiently waiting their turn.

larrystone 06-04-2008 08:42 AM

Re: gear ratio
 
Quote:

Originally Posted by TeamRinaldi (Post 2750599)
I agree, you could have anything. My '85 has a 305 and for a little while a longer the three speed, and has 2:73 gears. 3:73's are in a box in the garage patiently waiting their turn.

Your truck is going to have a lot more pep off the line with the 3.73 and a 4 speed OD. My 1992 came with 3.08s and the chage to 4.10 gears converted it into a real work truck but my highway mileage when from 25mpg to 18mpg.

But I doubt you will get any better fuel mileage vs. the th350 2.73 setup except if you are a flatlander and the torque converter lock up is operative.

My 1986 gets 22mpg at 60mph with cruise control. With fuel at $4 a gallon you might want to keep running that stock 305 for I it's my opinion that some of the "high output small blocks and "big blocks" are soon going by the way of the dinosaur.


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