My next 4x4 project is going to be a full size Bronco. I
something that will pull a 6000 lb. trailer, with good off road ability
and a removeable top. The last Bronco that had a removeable top was the
1986 model. After that, the rear shoulder belts anchored in the top, so
removing it was tougher.
I found an '86 with a tired 351 windsor, C6 transmission and a 9" rear.
The transmission slips, but C6's are an easy rebuild, and I just happen
to have a 351 Cleveland that will drop in with a few minor mods.
First step is to freshen the 351C.
This one is an abused crate engine that starved for oil, siezed
the center cam bearing, broke the cam and sat in someone's garage for
That's a 4V intake on a set of 2V heads. Probably ran bad due to vacuum
leaks. Notice the mismatch below.
After dissassembly and measuring everything, I found good cylinder
walls and pistons, but the cam bearing metal made short work of the
crank journals. I dropped the crank at the machine shop, who machined
it .010" undersize on the rod journals and .020" on the mains.
There is a difference between 2 bbl Cleveland heads and 351M heads, in
the exhaust port. Notice the bulge in the 'M' head above the exhaust
valve guide boss (lower). I don't know what this does to flow, so I
used the Cleveland heads.
I spent just a little time in the Cleveland heads, smoothing rough
edges and grinding away the thermactor bump in the exhaust port.
I wanted to do a 3 angle grind on the valve seats, but the 2.05" intake
valve doesn't fit the seat too well. Notice how low the gray line is in
the intake seat. This is from lapping compound.
There's not enough room to do three angles with this valve. A 2.19"
intake would work much better.
The exhaust valve and seat worked out fine. The bronze guides were
already installed, by the way...
Cleaned the pistons, quick honed it for cross hatch, and installed new
rings and ARP rod bolts (most bottom-end failures in Fords are rod bolt
failures), and installed the pistons...
I modified the points distributor to Duraspark II by installing a
plate, reluctor, pickup, springs and upper shaft from a DSII
Installing the Edelbrock Performer intake. The Edelbrock actually has
smaller ports than the 2V heads. If it were a race motor, I'd port
match. Actually, if it were a race motor, I'd scrap the Performer and
go with a better intake anyway. The felpro 1240 gasket is the correct
one to use (instead of the tray type) with an aluminum intake or if you
are building a Windsor with Cleveland heads (note the Windsor water
port in the intake face). I glue the gaskets in place with small dabs
of trim adhesive.
Now, here is a critical step in preventing oil leaks in Fords. It has
to do with the proper installation of the cork end rail gaskets
supplied in the intake set. Watch carefully...
Here is the right way. Use black RTV. I apply a 1/4" bead like so...
Starting to look like an engine...
Adapted a GM R4 A/C compressor. These are cheap, plentiful and short
enough to sit in front of the distributor and head...
I added a tang on the power steering bracket for the lower support.
Extended the oil pump pickup for the rear sump 4x4 pan...
The rod cap gets close, but should be fine.
The transmission options were limited to the stock C6, converting to a
T18 four-speed or an AOD. The AOD was out of the running quickly, as
too many parts would have had to been changed to make it work. The T18
would have been a good swap because of the granny gear, but for the
same money, I decided to rebuild the C6 with E4OD parts to get full
roller operation and wider ratios.
The Wide Ratio kit from Broader Performance in the foreground, and the
C6 components replaced in the back...
The symptoms in the tranny was a slide shift into second and judder in
1st under hard throttle. At first I thought that the dented trans pan
was causing it, as the imprint of the filter sump could be seen...
But then I got to the foward clutches, which were smoked, and when
dissassembling the valve body I found a broken spring in the 1-2 shift
Misc overhaul shots...
Out with the old, in with the new. Believe it or not, the Cleveland is
actually a newer design than the Windsor....
Engine and trans in, engine running. As expected, the Cleveland motor
trades a little low end torque for better midrange.
When researching exhaust options, I found Blackjack headers available
for the M and 400 engines in '80s Broncos. The problem was the primary
tube diameter listed was 1.5 inches. The 2V Cleveland exhaust ports
measured 1.75 inches tall. I decided to go with M manifolds and a Y
pipe. This created a few problems. The right M manifold will hit the C6
...So I ended up using a car manifold on the right and chopping a Y
pipe to shorten it for the Cleveland.
A/C line was a mix of Ford and GM components. It's a little loopy, but
Found a 9" traclok in the boneyard, it was rebuilt with new clutches
and installed in the rear.
Got to try it out recently, up in the mountains after a rain. The road
was washed out in spots, but the traclok-equipped Bronco handled it
This is why I've been waiting to paint it...
Trail pinstriping will usually wipe right off. I've been thinking about
just shooting it satin desert tan for this reason.
That's it for now!