82 blazer factory gears

[madman]

Hey guys i just bought a 82 blazer with a 4 inch lift and 35's. I t had a 305 with a automatic in it and it was week so i swaped in a 350 and it still feels underpowered on the hills. My 75 has a 350 in it and it pulls good for 35s and 3.73's even on hills . So I am thinking that i must have some high gears in this thing. What gears were available in 82 with a 305 (if it matters). I have a set of 3/4 ton axles off a 76 chevy with 4.10's that i was saving for the 75 but i thik this needs it more. How would the 4.10s work for me with the 350 automatic?

 

[dave_90_blazer]

look at the RPO code(starts with GU) in the glove box and post it up, but I would not be surprised if it has 2.73s in it

 

[ColAdo82K5]

My 82 which originally had a 305/700 had 3.08 gears.

It now has 350/350 with 35's and 4.10's. It works well overall but lacks overdrive for those long highway trips.

Blake

 

[madman]

THanks guys I looked in the glovebox for the RPO code but it was not there it has been peeled off. Now when you said that you would not be surprised if it had 2.73's is that right or did you mean 3.73's. This thing is a real dog compared to my 75. I drove the 82 to work today (10 miles one way) but there are a bunch of small hills that almost stop me. Ill be going about 60 then a hill comes and it is down to about 30mph. Is there any other way besides pulling the cover that I can tell what they are? Thanks again.

 

[RustBuket]

Believe it or not, they did put 2.73 rearends in some trucks....holy crap what a bad idea!

 

[4xrick]

well if your motor is kinda tired that will make a huge difference. but 90% came with 3:08s so that would be my guess. lift one tire off the ground and spin in 2 times and see how many times the driveline spins around. didide it and you get your gear ratio.

 

[madman]

Thanks again guys. 2.73's WOW! I couldn't imagine those being very good in a truck. 3.08s would be my bet but Ill check it out.

 

[1985_K5_Silverado]

Thanks again guys. 2.73's WOW! I couldn't imagine those being very good in a truck. 3.08s would be my bet but Ill check it out.

Not positive about '82, but in '85 2.73 was stock in the gas Blazers, with a 3.08 in the diesels. Fuel economy and all that jazz. I think the Blazers have a GVWR of 6100 (gas or 6250 (diesel), which puts them well below the 8500 GVWR threshold and thus makes them subject to the CAFE hammer that Uncle Sam dropped on us back in 1975. If only they had based the Blazer on the heftier K20 or K30 instead of the K10, but that's another topic entirely.

Luckily, my '85 was ordered by the original owner with 3.73 axles (RPO GT4), so it moves out pretty well from a dead stop with the 3.06 first gear in the 700R4 trans, but still gets OK mpg in overdrive on the highway for a boxy truck.