will a 6cyl pull a 4 or 5 speed transmission?

[06C2S]

Looking to buy my first Bronco and have found a couple that are clean. One a 69 No rust at all but a straight 6 with 3 on floor. Not looking to go fast but driving 70-80 on drives from SoCal to ID is a must. Will the stock 6 do that with a properly built 4spd. or a 5spd.?

The other is a 70 not as good shape but 302 with 3 on floor, I know this will pull it with the proper transmission.

Price is the same on both. Thanks,

 

[Nothing Special]

You ARE looking to go fast. 70 mph in an early Bronco is fast. 80 mph is really fast. I've got a 302, 4.10 gears, 33" tires and an NV3550 5 speed trans. It'll go 80 mph (turning about 2600 rpm to do it). But it's spooky driving an old truck that fast. I rarely go above about 60 with it.

I don't have any experience with the 6 bangers, but I'd think they could push a Bronco faster than would be safe, given the right gearing. Most 4 speed manuals aren't overdrives, so unless you're talking automatic there you probably want to go with a 5 speed. Or you could go to taller axle gears and get a 4 speed with a granny low to compensate for them on the low end.

 

[B RON CO]

Hi, if you need to go over twelve hours each way get an early Bronco and put it on a trailer.
Or get much newer big Bronco if you need to drive that far.
Good luck

 

[norm02]

Looking to buy my first Bronco and have found a couple that are clean. One a 69 No rust at all but a straight 6 with 3 on floor. Not looking to go fast but driving 70-80 on drives from SoCal to ID is a must. Will the stock 6 do that with a properly built 4spd. or a 5spd.?

The other is a 70 not as good shape but 302 with 3 on floor, I know this will pull it with the proper transmission.

Price is the same on both. Thanks,

I’m not aware of any 4 or 5 speed transmissions that will adapt to the six cylinder but I could be mistaken. One thing to consider is the fact that if the six is original (not modified for performance) it will probably not be able to maintain 70mph in 4th or 5th gear (assuming there’s a trans that will adapt) unless you have it floored on flat ground depending on how tall the overdrive gear is.. This is assuming tires larger than 31” tall.

If you’re wanting to cruise at 70mph-80mph for hours on end and with no fuss, than you’d be better off to go with the 302ci and swap in an AX15 or an NV3550.

 

[Timmy390]

You'll need more than the V6 that came in the Bronco. Neither the 170 or the 200 will do the job being ask. Just weren't designed to do the ask.

If I'm not mistaken, the 6 cyl Broncos all came with 4.10 gears factory. You could do a V8 conversion on it as you need a new engine and trans anyway. You need 4.10 or lower gears no matter the engine/trans combo unless sticking with stock size tires.

Or buy the V8 and rebuild the engine or crate motor. The go with a 5 speed trans and swap gears.

Transmission swaps are all unique and most require new driveshafts. Some swaps are easier than others but easy don't mean that's what you need.

Tim

 

[spap]

Also with both you will be getting maybe just maybe 10-11 miles per gallon.

 

[okie4570]

You'll need more than the V6 that came in the Bronco. Neither the 170 or the 200 will do the job being ask. Just weren't designed to do the ask.

If I'm not mistaken, the 6 cyl Broncos all came with 4.10 gears factory. You could do a V8 conversion on it as you need a new engine and trans anyway. You need 4.10 or lower gears no matter the engine/trans combo unless sticking with stock size tires.

Or buy the V8 and rebuild the engine or crate motor. The go with a 5 speed trans and swap gears.

Transmission swaps are all unique and most require new driveshafts. Some swaps are easier than others but easy don't mean that's what you need.

Tim

Yes correct either 4.11 or 4.57

 

[DirtDonk]

Except for the "V6" part of course... But we knew what he was talking about.;D

And welcome to classicbroncos too 06C2S. Agree with the others that say for what you want, the V8 is quite literally the only way to go. The Early Bronco six cylinder engines were fun, but pretty anemic by any standards. Fine and fun for around town, the beach, or the ranch. But not fine OR fun for the long freeway drive.
And wait until you hit a hill with the extra pounds of gear for your trip. You'll remember the old phrase "I could'a had a V8!" real quickly.

Good luck whichever route you go.

Paul

 

[bmbm]

Kind of depends on which six as the amount of cubic inches is important. And what size tires. But you mentioned a 69 Bronco which may have had a 170 don't remember when the 200 became the base motor. But either would struggle with an od trans. With a 250 six and NV3550 and 30" tires I got my 66 to close to 80 just once for fun and I backed off because or reasons previously mentioned. Cruising along 65-70 on the freeway is fine. On the steep grade up to Tahoe it will easily pull past 70 in 4th but is high rpm and noisy (no floor coverings). You might be happy with an 302 and an AODE.

 

[okie4570]

I know the 66' u14 I had with a 200 6cyl, 3sp manual and 4.57 gears was absolutely wound tight at 55-60mph

 

[Quick & Dirty]

When I first got my Bronco it was my daily driver, the only vehicle I had. I drove it from Wisconsin to Arkansas a couple times a year to visit my parents. A 10 hour drive. I'd run the rebuilt 351 at 3000 rpm, which was about 75 mph with the C4, 3.50 gears and 31" tires. Occasionally push it to 3500 rpm in the fast lane. Certainly not as comfortable as a newer car, but nothing I felt afraid of doing.

 

[Broncobowsher]

The transmission won't make up for the lack of engine power.

Yes, there are a few ways to put a 4-5 speed transmission in. NV3550/AX15 adaptor to the stock Ford bellhousing, just find the correct clutch disk. Get a 250 I6 from a later model with the small block bolt pattern, pretty much any small block adaptable transmission is possible. Not really what you want for a freeway flyer but the NP435 has been put behind the I6 more than a time or two.

It's just the 170/200 I6 that was stock just doesn't have the ponies needed to move a barn door through the wind. They were underpowered when stock and thus the extra low gearing in stock trim. When new and in perfect condition you might get one to 80 on perfect day. You are not going to drive in LA traffic with one.

 

[AC932]

Stock 302 with stock 3 speed will run 80 all day with no issues. Do 60 on stock tires and you can get 16-17 MPG. If your main goal is driving to idaho, go with the V8.

 

[06C2S]

Thank you for all the replies, Helped me make the decision. V8 it is, hopefully will have pictures of my new purchase soon.

 

[73azbronco]

55 top speed, maybe 65 downhill. 35-40 uphill, but all making 16mpg

 

[Speedrdr]

Had a '70 that had a 200 Six when I bought it. Had .410 gears. 4 wheel drums. Would it run a steady 70 mph? Absolutely! Did it scare the snot out of me? Hell, yes! Fast forward a few years to a 350 HP built 302. Same gears, sam brakes. Run a steady 70+ MPH? Yep. Still scare the hell out of me?? You bet. Only difference was it was easier to do the 70 mph. Lol.
Randy

 

[blubuckaroo]

More gears is always better, but just adding an overdrive tranny without considering the differential ratio and tire size is just going to end up disappointing. You'd need to re-gear your differentials as well.

This reminds me of the time I put on a smaller rear sprocket on my Honda Trail 90, so it would go faster. The end result was it was more sluggish and the top speed was reduced, because the engine didn't have enough power to pull the higher ratio.