'87 Bronco II Rugged V8 Build

[Dirdy Dan]

I love these little trucks. My old '88 from high school was a blast. 5-speed with 4.10 gears. I ended up finishing it off with a dunes trip and wrecked it. Had another '89 for my ex, and it was an electrical nightmare.

This one will be my dream little 4x4. It's in fairly good shape for a Michigan truck. I want a solid, safe, and dependable wheeler I can read trip anywhere and back reliably. Picked up a very clean '07 F150 frame today. Its gonna be stiff

5.8 roller cam, carb
M5OD
1356
EB D44 front
Narrowed 9.75 rear
Extended tubular radius arms
EB lift coils
Chevy rear leafs
Detroit Tru-Trac front and rear
4.56 gears
33" tires to start


Front axle will be forward a couple inches, and rear will be back a couple. I'm fairly sure I will be able to finally use my Mustang full length headers I have had for over a decade. With a large open frame, I have plenty of room to put the engine down low.

Preliminary measurement findings conclude I need to remove about 50" out of the center of the frame, and narrow it about 5.5". The front crossmember will need removed and relocated for the steering box. The rear will need to be shortened in a few places. The stock tank will fit. And most cab mount locations need tweaked and raised. A couple will bolt directly to the frame. Should net me a very rigid, very open frame.

And here is the truck. Also another donor frame for parts, and now measurments.

The front axle is heavily trussed, Yukon chromoly shafts, 4.56 gears, Detroit Tru-trac diff. Rear will be the same.

 

[Jim Oaks]

Well, this is going to be interesting....

 

[franklin2]

The full size f150 frame is just a larger version of the Bronco frame. In my experience, the f150 frames are not that rigid since they are still a open channel type frame. If you boxed the original Bronco frame it would end up being more rigid than the open channel f150 frame, even though the f150 frame is larger. And or weld in a roll cage to the frame to stiffen it up.

I thought possibly you where using the large truck frame to utilize it's larger axles and their mounting points, but if you narrow the larger frame you will be losing that advantage.

 

[Dirdy Dan]

2007 F150 frame. From '04 on, they are fully boxed. And these frames are ridiculously wide to be used with a B-II full width. The body mounts would start to be inside the frame rails.

I have to narrow it 5.5" because that's the minimum I need to use the early Bronco front axle I have. It will still have 30" between the frame rails in the engine bay.

I do plan to buy a 1-5/8 die for my tube bender and make a simple cage.

 

[franklin2]

Ok. You are basically using the f150 frame for the steel instead of going to the metal shop and buying new tubing.

 

[Dirdy Dan]

Yep, a hydro formed, fully boxed frame. One I can shorten at the slip connection, where the front and rear section join, and attach the rear section , while fully retaining the S-curve sections. I can also use the body mounts, which can easily be relocated. And all the crossmembers, but the front, can be shortened and re-used. The upper control arm mounts can easily be modified into coil spring buckets. The design of the frames tubing is far superior to a straight rectangle tube. And honestly, this will be easier and faster for me to do. Will save me money in steel tube, save time in laying out a new frame, require less than half the welding, ect.

 

[Dirdy Dan]

Got so many other projects done, it's this ones turn for attention. Frame is up for the initial strip down. Got the bare rolling chassis next to it for measurements

I actually just got done taking everything off the F150 frame. I'm about to cut brackets off now, and prep it for more surgery. I will only be cutting it up on the trailer. I have a couple large beams I will use for a straight, level, surface to weld it back together. Meantime it's nice having it up in the air.

 

[Dirdy Dan]

Got so many other projects done, it's this ones turn for attention. Frame is up for the initial strip down. Got the bare rolling chassis next to it for measurements

I actually just got done taking everything off the F150 frame. I'm about to cut brackets off now, and prep it for more surgery. I will only be cutting it up on the trailer. I have a couple large beams I will use for a straight, level, surface to weld it back together. Meantime it's nice having it up in the air.

 

[Dirdy Dan]

I have to narrow it about 8" to use the EB D44. A little more than I thought. Good news is Ford has not changed their general frame shape since 1980. The cab mounts are in the exact spot in relation to the front axle centerline, and core support. Bad news is the rear is more streamline and I can't find a way to make it work without cutting it to pieces. So I can use the entire front section, cut out the middle flat area, and use the frame to the end of where it steps up in the rear. At that point, it's possible to integrate some of my original frame ideas.

I could use the rear of both Bronco II frames and make a boxed frame to mimic the F150 frame and attach it. It gives me the correct size rectangle I need for the rear and makes fitting a factory gas tank very easy.

Or use some 2x5 rectangular tube I have and just straight tube the back.