Any viable way to make the 170 drivable with 35s?

[John_parkeriv]

So I'm getting to the point where I can start planning the engine for my Bronco build. The original plan was a 351 Windsor with a 5-speed behind it and 35's on a 4.5" lift. The lift is already installed. Right now I'm having problems finding a 351, but I do have the original 170 in my truck that ran when I got it.

My question is is there any viable way to get the 170 to run on the road (around 60 mph), without taching 5000? I wanted to add an overdrive, but I'm worried the 170 hasn't got the torque for it, and especially not with 35's.

If all else fails I'll just continue with the 351, but have y'all got any ideas?

 

[fordfan]

A 170 is great at rural cruising speeds and original size tires (what the Bronco was originally designed for).. Anything over a 30" tire and the 105 hp is puffing. With a 200, 31" or 32" tires are OK.. not great but OK. Go up to a 250 and they tell me 33" tires aren't bad.. I don't personally know. My advise is 35" tires and a 170 is going to render your Bronco very inadequate and take all the enjoyment out of cruising it..

So, your guess is correct, the 170 isn't for 35's...

 

[John_parkeriv]

My advise is 35" tires and a 170 is going to render your Bronco very inadequate and take all the enjoyment out of cruising it..

That's what I figured. It seemed great on the stock tires at 35/40 but struggled at 55. I just wanted to see if anyone's got a build for more power (stroker/boring/etc.). I just don't think there are many speed parts for it.

 

[sanndmann3]

i would go all in on 351 or double down with a 408 but if sticking with 170... don't fear the gear.

 

[Broncobowsher]

170 and 35s? No, it isn't going to happen. You could drive it around town, but it won't push highway speeds.

 

[Speedrdr]

170 and 35s? No, it isn't going to happen. You could drive it around town, but it won't push highway speeds.

Not to be appearing argumentative here, but I had 72 EB with 4” lift and was running 9.00 X 16 Co-op grip spur mud tires that were 36” in diameter. Had an ‘upgraded’ 200CID six with 4.11 gears. I personally think that if you have relatively flat terrain (I lived in the MS Delta at the time) you can run highway speeds relatively easily. No, it’s not gonna win any drag races but it won’t run 5000 rpm at 65-70 MPH. I had no problem with the 36” skins until I moved out of the flat terrain. At this point, the steep hills kept me rowing through the gears. The hilly area led to a crankshaft that spun in the main bearings.
I’m not saying the tall tires and a 6-cylinder 170 or 200 CID is a good or smart option, but it CAN be done.

Randy

 

[gnpenning]

The easiest, cheapest and most reliable way no matter the terrain
is to install a tow bar....

You would have to go deep with the gears even then as you mentioned having the torque would be another story.

 

[Madgyver]

regear correctly for tire size.

 

[ntsqd]

I ran ~100 HP and 33's under a similarly shaped brick but not an EB for 125k miles, give or take a few. It was slow, but not to the point of being a danger to myself or others. That truck did have 4.88's in it and had an OD.

I must admit to being mystified by those who say it won't work. It is true that I had 5 speeds and deep axle gears, and that would be a requirement for it to work. With the stock 3 spd you would be hurting for gearing options and would likely have to go slower than you'd like at certain places.

A 250 would be the better bet though because it puts you into the same bellhousing that you're going to need for the 351W.

 

[MonsterBIlly]

Gears, install 4.88s or 5.13s and you will be fine

 

[svobronco]

Paxton...

 

[rjlougee]

A turbo isn't incredibly difficult to put on the exhaust manifold, since it's the single outlet log style.

Looking on Ebay, 5.0 twin turbo setups use a hybrid T3/T4 housing set up

• 50 A/R compressor housing
• .63 A/R turbine housing
• .57 compressor wheel

What little I remember of my 300 inline turbo research seems to support that size (Forced Induction and Maximum Boost).

Probably a lot more work than building/installing the 351W....
HTH, Joe

 

[EB70]

Gears are your friend. I have a lot of experience with gutless 4x4's with big tires. Gears are always night and day. 4.88 minimum and it should be fine.

That being said, my DD EB has 4.56's with a stock 302 and headers with 37's that are heavy. It is relatively efficient and easy peasy to drive.

For the longest time, I have been an advocate for just gear it with underpowered rigs and larger tires. Now that I have a large hill to climb to get home and so forth I do prefer the power of a decent engine. The other underpowered vehicle I built was a little stressful to drive. A headwind, check your speed. A close pass, don't do it. etc. Great around town and it had other advantages but straight HWY was not that great.

Running an underpowered rig caused me to think alot more about the art of driving and a little less about just enjoying the ride.

My "normal" EB is much more fun to drive and when one needed to be sold it was no question, the underpowered one went.