What gears?

[Wicked Wolf Auto]

I need gears BAD! but which ones. I need it to still be streetable... I'm currently running 35's but will be upgrading to a 37 or 38. 350/350/203 will be 205 hopefully soon. And I'm currently running 3.73's cruising at 35 Im at 1400 RPM's I'm thinking 4.56's any opinions?

 

[Chaddy]

I dont think I would go with 4.56 with your 350trans mabey try 4.10.

 

[Z3PR]

4.10's are not really that big of a jump from 3.73's. I'm thinking 4.56's or even 4.88's, keeping in mind those future tire sizes.

 

[78Suburban]

Hijack:
alf4444, just curious, how are the 3.73's with 35's? are they gutless and unlivable? does your tranny have overheating issues? I have 3.73's, and I am struggline between 33's and 35's, becaues the money for a gearswap isn't in my near future. thanks

 

[trailblazr81]

Definatelly 4.56 or 4.88 gears. Ive run both with TH350 and 35's. 4.56 with 35's in a 81 K5, and now 35's with the stock 4.10's in my 73 K20. I plan on moving up to 38's and swapping in 4.88's. Also how much freeway driving you doing? Back when I had 4.56 in the Blazer I mostly drove in town and it was my DD. Now my 73 K20, is only driven for fun, or to make runs to the dump, so I will probly put more gear in it than if it was a DD. I wouldnt go higher than 33's with 3.73's if I wanted to really use it. You can do 35's but it wont be fun. When I first lifted my 81 I was running 35's with like 3.08 gears. That was a dog. I had a 383 in it and manually shifted the TH350 but it was night and day swapping in the 4.56's. My cousin had a 92 Z71 with 3.73's and 36's for about 8 months. Not a good combo!!

 

[Wicked Wolf Auto]

Hijack:
alf4444, just curious, how are the 3.73's with 35's? are they gutless and unlivable? does your tranny have overheating issues? I have 3.73's, and I am struggline between 33's and 35's, becaues the money for a gearswap isn't in my near future. thanks

I haven't had any tranny problems But definatly need more torque I'm running 300 hp so I won't say it's gutless but could do better with gears

 

[Wicked Wolf Auto]

Definatelly 4.56 or 4.88 gears. Ive run both with TH350 and 35's. 4.56 with 35's in a 81 K5, and now 35's with the stock 4.10's in my 73 K20. I plan on moving up to 38's and swapping in 4.88's. Also how much freeway driving you doing? Back when I had 4.56 in the Blazer I mostly drove in town and it was my DD. Now my 73 K20, is only driven for fun, or to make runs to the dump, so I will probly put more gear in it than if it was a DD. I wouldnt go higher than 33's with 3.73's if I wanted to really use it. You can do 35's but it wont be fun. When I first lifted my 81 I was running 35's with like 3.08 gears. That was a dog. I had a 383 in it and manually shifted the TH350 but it was night and day swapping in the 4.56's. My cousin had a 92 Z71 with 3.73's and 36's for about 8 months. Not a good combo!!

I will be doing more and more freeway driving when it's done to get to trails but for now it's mostly on city streets so you think 4.88's would be okay untill I get my 38's?

 

[Wicked Wolf Auto]

I dont think I would go with 4.56 with your 350trans mabey try 4.10.

why not and where the hell is white city?

 

[jekbrown]

5.13s.

j

 

[dyeager535]

More than anything I think you need to base it on what you can tolerate from the engine, or how slow you can stand to cruise. 2500RPM or so is my upper limit for 60-70MPH cruise, I just don't think my engine needs to spin that fast, even though it can. But with no overdrive, well, I digress. I just don't go any higher than about 65MPH.

I used to be of the opinion that using the gears to net good freeway manners was the way to go, but that very much affects what kind of compression braking you get, so in your case I would go as high numerically as you can stand. (this is why OD is so nice ) For a street only vehicle I could care less about compression braking, even if acceleration suffered a bit.

 

[trailblazr81]

Well with 35's 4.88 gears will put you just under 2600 RPM at 55MPH. With 38's almost 2400 RPM. 4.56's will be a hair over 2400 RPM on 35's and with 38's a li'l over 2200 RPM. If you plan on doing 38's you should go 4.88's. And you'll really like yer Hole Shot with the 4.88's!! Also have you done anything to boost your HP and torque?

I'll cruise on the freeway 2500-3000 RPM depending on how big of a hurry I am in. Tho it maybe see's 45 minute highway drives once every month or two. But I have a pretty good motor and dont mind the noise.