What gear ratio for street

[Broncobowsher]

I'd still give it a shot with the present 4.11s. If you are lugging the motor, into the convertor a lot, that's when you need more gear.

I agree that the 4.11s are a bit on the high side. And I am all for the "don't fear the gear". But there is also times where close is close enough and the gains don't justify the costs.

 

[browngr5]

Thanks guys,
I just need to stop messing with it. I was happy with the torque before this 5.0 Trick Flow kit.

I know now that the 1990 5.0 with stock 19lb injectors, stock heads and intake with a E303 cam, 1600 converter, is my favorite combo.

 

[H20rider]

I have a ‘68 with a 4 speed toploader (no overdrive) and a mildly built 302 on 29” tires and 4.11 rear end (no posi) and 2.5” lift. No offroading. Freeways are too fast as I get about 55mph at 3,000 rpm. I like the quickness I get on the streets, but am wondering about getting a bit more top end.
350 rear end? I worry that the truck will be sluggish, though. Other suggestions?

 

[Speedrdr]

I have a ‘68 with a 4 speed toploader (no overdrive) and a mildly built 302 on 29” tires and 4.11 rear end (no posi) and 2.5” lift. No offroading. Freeways are too fast as I get about 55mph at 3,000 rpm. I like the quickness I get on the streets, but am wondering about getting a bit more top end.
350 rear end? I worry that the truck will be sluggish, though. Other suggestions?

Have you considered going up to 33’s on the tires? I ran 33 12.50 15s and/or 35 8.00 16s on a 320 HP 302 with 3 on the tree and 4.11s. 60 mph was about 2400 RPM if my memory serves me correct. I sure would not want to go to the 3.50s…but that’s just me

Randy

 

[Speedrdr]

And I sure don’t like the 3.50 that’s what I’ve got in my current EB. Looking to go to 4.11s or better.

Randy

 

[DirtDonk]

Did you verify your speedometer is correct? Verify at least in general that your tach is correct? It seems right, using the calculators, but I figured I'd ask anyway.

With the 3.50-ish ratio you lose about 600 rpm. So that might put you into a nice area for all around driving. Yes it will be more sluggish, but with only 29" tall tires, it really should not feel like you lost much power.
But before you change any gear ratios, be sure you're dead set on never changing your tire size. If you decide later to go up in tire size after all, those 3.50's that felt decent now are really going to make you sad.

And of course, if you do decide to change ratios, just change the rear end first. See how you like it, then follow up later with the front when you settle on a ratio for sure.
And now for the PSA... Instead of changing gears (especially if yours are in great condition still) why not just (hah! I said "just" with a Bronco!) change to an overdrive transmission instead? It's probably about the same money yet gives you more versatility.
Just a thought...

Paul

 

[triracer67]

I run 4.56 with 33s, 351w,C4. It’s a blast around town, and pretty good for highway. I run about 3100 rpm’s at highway speeds and have gotten used to the motor singing. Honestly, I think it’s the perfect gear for a cruiser. I do guzzle down some gas…

 

[H20rider]

Did you verify your speedometer is correct? Verify at least in general that your tach is correct? It seems right, using the calculators, but I figured I'd ask anyway.

With the 3.50-ish ratio you lose about 600 rpm. So that might put you into a nice area for all around driving. Yes it will be more sluggish, but with only 29" tall tires, it really should not feel like you lost much power.
But before you change any gear ratios, be sure you're dead set on never changing your tire size. If you decide later to go up in tire size after all, those 3.50's that felt decent now are really going to make you sad.

And of course, if you do decide to change ratios, just change the rear end first. See how you like it, then follow up later with the front when you settle on a ratio for sure.
And now for the PSA... Instead of changing gears (especially if yours are in great condition still) why not just (hah! I said "just" with a Bronco!) change to an overdrive transmission instead? It's probably about the same money yet gives you more versatility.
Just a thought...

Paul

 

[H20rider]

An overdrive transmission….yes….funny you should mention that. My transmission saga is too long and boring to go over….but, for now I will stick with the newly rebuilt toploader. Sounds like bumping up tire size is the way to go…..at least for now. In the meantime, the truck is soooo much fun on the streets.
Thanks

 

[blubuckaroo]

If you want to run tires in the 29"-31" size, and want to keep the three speed auto or manual transmission, 3.70 or 3.89 gears would probably be more appropriate to keep a factory RPM.
Here's a good gear ratio/ tire size calculator that covers all the gear ranges rather than just high gear.
https://spicerparts.com/calculators/transmission-ratio-rpm-calculator