35s or 37s? And which hydro boost? Wild horses or Jame Duff?

[SteveMa74]

I’ve been wheeling w/ 35s For a few years now (up from 33’s). I have a small crew of guys I roll with here in NorCal, two modern 4 door jeeps, one running 37s, and one running 40’s…heavily modified), an FJ60 running 37s, and an older two door jeep running 37s (but with tons of lift, and plenty of ground clearance). And an older two door jeep w/ 35s. I’m getting the friendly nudge to go 37s! We recently did the snake lake loop up at Gold Lake. Typically do 2-3 wheeling trips a year, one of which is a snow wheeling trip. My brakes suck. Have the four wheel disc conversion, but still running vacuum boost. I’m getting ready to order a hydro boost unit. Both WH and James Duff seem to have comparable units, and I like how they both have youtube videos (JD’s being more instructional). Plan to do that install myself. Did the power brake booster install myself many years ago. But today, the truck just doesn’t stop well. Any suggestions between the two?

And I know 35s vs. 37s comes with so many other questions…..what type of wheeling do you do, what’s your set up etc. But I’ll give it a try: I have an older Cage 3.5” suspension lift, 1” body lift. fiber glass flares which I need to now replace (and prob will re-install gorilla flares higher up the body line, since I’ve torn up my fiberglass flares stuffing my wheels into the wells). I have Dana 44 front and Ford 9 in the rear (4.56 gears w/ ARB lockers front and rear). I did upgrade my axle shafts a while ago. Can’t recall honestly if it was to 30 or 31 spline, and what type). I’m running a ford racing crate 302 that produces around 380HP, mated to an NV3550, and a Dana 20 w/ the Tera flex gear reduction set (3.15).

So I know the hyro boost brake upgrade is a must. I’m already going to order new fender flares (flexible, not fiberglass) that I’ll mount a bit higher on the body line. BUT….will I need ram assist steering? Will I need to upgrade my axles to 35 spline? And right now I feel like i have a pretty good balance of crawling speed but can still drive home at 65 mph (when my steering geometry is right!). Note I do have the upgraded Clydesdale drag link and tie rod from WH. And I’m heavy on the gas pedal. “Feathering” my gas pedal, is not something that seems to be in my vocabulary. I’m a bit heavy footed out on the trails when it comes to coming off the clutch. Especially when I’m pointed uphill, and nervous about rolling backwards.

Would love some thoughts. Can my set up “as is” handle 37s? I little extra belly clearance in the snow would be nice, and a little extra clearance in the rocks would be nice too! But so far, I’m largely keeping up w/ my crew. But the peer pressure for bigger tires is mounting (pun intended).

 

[SteveMa74]

Pics of my bronco

 

[1969]

You can save some money and get an Astro van hydroboost unit. Lots of write ups on here on how to do it.

I think you’ll be fine putting the 37s on if you plan to raise the fenders a bit.

Side note.. Are you running fuel injection of sorts or carb?

 

[SteveL]

There's a set of warflares in the classifieds. If you upgraded the rear axles it's probably 31 spline. They don't make a 30. They come 28, 31, or 35 spline aftermarket. I think strange makes a 33 but they're rare to come across.

 

[Shimmy]

you'll be happy with either hydro boost kit. both use brand new hydro units. i have the WH kit and i'm happy with it. no complaints here. when i bought mine i think the WH moab kit was the most complete kit available? i wasn't interested in piecing together parts from other cars or used units. I barely have time to install this stuff myself, so i wanted the simplest, quickest to obtain kit out there.

 

[gnpenning]

When you say your "brakes suck" what does that mean? Can you lock up all 4 or ?

What master cylinder/ portioning valve?

You might have more going on that the hydro boost won't change.

As far as you being worried about rolling backwards when climbing, put a gear shifter off a bike on your transmission shifter so you have a hand throttle. Not hard to do and might save you some stress and parts.

Looks like you have a nice EB.

 

[lilthom]

I've got the JD kit and can state that it will stop in 48' from 40 mph. Mine is the one used for their video so I am biased. I can't add to the other comments but I will second adding the throttle control to your shifter. You can keep one foot on the brake, one on the clutch and one finger pulling back just enough on the gas for a smooth acceleration up that hill or over the obstacle.

 

[SteveMa74]

You can save some money and get an Astro van hydroboost unit. Lots of write ups on here on how to do it.

I think you’ll be fine putting the 37s on if you plan to raise the fenders a bit.

Side note.. Are you running fuel injection of sorts or carb?

Running fuel injection. Thx for the reply!

 

[SteveMa74]

When you say your "brakes suck" what does that mean? Can you lock up all 4 or ?

What master cylinder/ portioning valve?

You might have more going on that the hydro boost won't change.

As far as you being worried about rolling backwards when climbing, put a gear shifter off a bike on your transmission shifter so you have a hand throttle. Not hard to do and might save you some stress and parts.

Looks like you have a nice EB.

Thx for the suggestion on the hand brake, I have a unit that I ordered years ago and it’s still sitting on the shelf, it’s the JB customs fab version…more like a know as opposed to a gear shifter, but time to revisit installing! And no, the brakes don’t lock up. Just will come to a rolling stop at full force. Can’t recall on the proportioning valve, but the Master cal was part of the kit i ordered years ago when I upgraded to power brakes/vacuum booster.

 

[lilthom]

Thx for the suggestion on the hand brake, I have a unit that I ordered years ago and it’s still sitting on the shelf, it’s the JB customs fab version…more like a know as opposed to a gear shifter, but time to revisit installing! And no, the brakes don’t lock up. Just will come to a rolling stop at full force. Can’t recall on the proportioning valve, but the Master cal was part of the kit i ordered years ago when I upgraded to power brakes/vacuum booster.

Not a hand brake, a hand throttle.

 

[1969]

Running fuel injection. Thx for the reply!

Which system?

 

[SteveMa74]

Not a hand brake, a hand throttle.

Yup, sorry, too early west coast here and mixed up my words…yes, the hand throttle. I had previously ordered one, and started to toy around with installing it, but need to go try that again.

 

[gnpenning]

While the HB is a good addition for larger tires, you need to find the root cause of your poor brakes first before adding anything else to the mix.

 

[Yeller]

Your plan will work, lots of factors for sure but sounds reasonable. 37’s will be harder on parts but really a lot of factors whether there will be issues or not with driveline durability. Everyone waits until they have problem steering to go to assist. I won’t build anything that gets a locker that doesn’t get assist, regardless of tire size. All you’re doing is asking for trouble, whether it’s damaged box, bolts, frame, etc, not to mention general drive ability. Track bar bushings last longer, steering box last longer, risk of broken frame is all but eliminated. Even my exploring truck has assist with no locker and 33’s. Just do it.

As for hydro boost, can’t go wrong with either kit.

 

[sprdv1]

Add some RCV axles up front

 

[garberz]

Add some RCV axles up front

Yup! Those Chromo axles will be the weak link. Definitely carry a spare set of front axles if you don’t upgrade to RCV’s.

Mark

 

[SteveMa74]

Yup! Those Chromo axles will be the weak link. Definitely carry a spare set of front axles if you don’t upgrade to RCV’s.

Mark

I thought the RCVs only worked with the larger hole in the 77 knuckles. Thought I saw that written somewhere, or maybe a jim creel youtube video. And if that’s the case, is it easy to swap over 77 knuckles in place of my 74 knuckles. and yes, RCVs would be awesome…..

 

[bmc69]

Not a hand brake, a hand throttle.

or how about both?.. ;-) with front and rear winch controls as a bonus.

 

[garberz]

I thought the RCVs only worked with the larger hole in the 77 knuckles. Thought I saw that written somewhere, or maybe a jim creel youtube video. And if that’s the case, is it easy to swap over 77 knuckles in place of my 74 knuckles. and yes, RCVs would be awesome…..

Yes, it is preferred to run the Ford disc and knuckles. But it can be done with the smaller drum knuckles. Duff sells the complete Ford disc/knuckle set up to convert over. I’ve had a few friends spend the money because they got tired of breaking stub shafts out on the trail.

Mark

 

[SteveMa74]

Yes, it is preferred to run the Ford disc and knuckles. But it can be done with the smaller drum knuckles. Duff sells the complete Ford disc/knuckle set up to convert over. I’ve had a few friends spend the money because they got tired of breaking stub shafts out on the trail.

Mark

Got it. Thx.