How big of tires can I get without changing gear ratios?

[weisel]

I have a 77 k5 with a stock 400 engine, th350 automatic tranny, 203 (or however you say it) transfer case, and 3.73 gears. How big of tire can I go, but still being able to push it around, and not messing up my alrady horrible gas mialige? Now this has nothing to do with lifts and such, I'm just talking about if it has enough power.

Insurred by Smith & Wesson

 

[bigerik]

At one point I had 3.73s and 33" tires, and it did OK. No way I would go over 35s with a 3.73:1 ratio, even if you had a granny gear. Why don't you want to switch gears? Too much $$?

 

[wayne]

35 would be the max with 3.73 gears if you want it to still move pretty good.

<A target="_blank" HREF=http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html>http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html</A>
<font color=blue>Happy Trails

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<font color=blue>Wayne</font color=blue>

 

[thatK30guy]

I had an 86 short bed K10 with 3.73's and 35's. That truck smoked those tires like no tomorrow. In fact, any ratio would work for any tire size. The thing I look at for tire spin is the strength of the motor. Anybody can get a 3.08 rear to smoke 44 inch tires as long as they had a peppy motor.

 

[CaptCrunch]

That would be one heck of a motor to do that w/ no granny gear

! But you are correct... depends on the power and torque of the motor as well as axle ratio... although freeway rpm also enters down the road and transmission gear ratios as well. A TH350 isn't anything special... But say you throw in a lower first gear ratio like a 700R4 has and that will really help off the line. We threw a steeper gear in my buddies TH400... all I can say is WOW

!

1987 Chevy K5 Blazer- 350 TBI

 

[dyeager535]

I'm running 33's with 3.42's, truck has no problem moving out smartly. Not gonna win any drag races, but I have no problem hitting way over 60 on a freeway on-ramp.

Dorian
My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>

 

[slider79blazer]

I have a 79 blazer w/35" tires. It has the 400ci. engine
350 tranny automatic with 3:73. I had 6.5 miles to the gal.
before, then I put a K&N air filter kit on. Also new distributor
cap and rotator. and headers w/ dual exhuast. I get between
8-9 gals. now but I might get better if I wasn't a lead foot.It made a big differance in power.I'm going to put on a throttle body injection setup on soon.
Let you know if it helps!!