I would use the 1992 crossmember that came with the trans. I just went through this with an M5OD 5spd swap in my 1984 F150 (gas). I had purchased a crossmember that was correct for the 5spd transmission, but it had come out of a 1994-1996 F150, and like you, the crossmember didn't quite line up with the holes in my 1984 frame. I slid the crossmember rearward so that the trans mount studs were centered in the mounting slots, and then measured where the holes needed to be in the frame (approx 1.25" further back). Drilled two new holes, then reinstalled the crossmember and bolted it down. For the gusset brackets that go from the crossmember to the top of the frame, I modified them slightly with an extension piece so that I could utilize the mounting bolts that were already in my frame (Those bolts couldn't be removed on my truck without lifting the cab, so I figured it would be easier to modify the brackets).

 

I did the exact same swap on my 89 diesel, except I had a donor 89 zf truck, so I had it a little easier. Did all the swapping you did. The lower crossmember for the c6 and the zf were exactly the same on my truck. But my truck already had a set of holes rearward drilled in the lower part of the frame c-channel, and when I used those holes, the lower crossmember for the c6 bolted right up.

The short upper crossmembers for the c6 would not bolt up. The short upper zf crossmembers from the other truck did bolt right in. The zf short crossmembers had more of a offset to them, since the lower crossmember had moved back about a 1 inch.

I had a plan, if I had to use the short upper c6 crossmembers, I was going to bolt them on the lower crossmember in it's new location, and then see which one of the two upper frame holes could be used, and mark the c6 upper crossmembers through the existing upper frame hole. Then drill a custom hole in the c6 crossmember and at least use one bolt to bolt them in at the top. Looking at it, I figure it would have been almost impossible to drill two new holes in the upper part of the frame with the cab in place.

Since I had a 89 donor, I found there is a plug under the brake booster where the transmission/transfer case harness plugged in. I unplugged my c6 harness, and plugged in the zf harness, and it all worked, no wiring to do at all. Not sure if you can get away with that on your truck, but I will warn you the manual trans harness has a jumper made in it right at the plug, to jump the two red/blue wires. These are the wires that go to the neutral safety on your c6. If you do not jump these wires after taking the c6 out, it will not crank over.

 

 

I did the very same thing. I found a 5spd crossmember from a newer truck (95+ I believe) and it had a very pronounced curve in it, and I was sure it was going to work. I still had to re-drill the holes. It was very close, but not quite close enough. I'm sure there's a better chance of an earlier crossmember fitting better (like an 88-91), but do let us know what you find out. I'm curious now. I was trying like hell to use factory parts that all bolted back in place, but it just didn't work for me. I only had to drill one hole in each side, so that wasn't so bad.

 

 

 

 

So long as you use some sort of upper gusset in some form or fashion. I think some people just use the lower crossmember and forget about the upper ones, that is a bad idea in my opinion. Together the upper and lower crossmembers hold the frame in a vertical position, which is it's strongest position when downward pressure is applied.

 

 

I would not ignore it. Most likely it is not the pinion bearing, it's the large nut has come loose. This is a common problem on the Ford Sterling 10.25 rearends. The splined area of the yoke is a little undersized, and they wear a little bit. This lets the yoke twist back and forth a little bit on the splines, and this loosens the nut. After awhile it will get so loose you get a oil leak, and you will also get vibrations in the "inbetween" mode when you are just lightly on the throttle.

All you have to do is take the rear of the driveshaft back out, take a impact gun and put it on high, and hit the nut a couple of times with the gun. You will be good to go for a year or two till it happens again. If you have a good parking brake or some way to hold the truck, you can also tighten it with a breaker bar with a long cheater pipe on the handle.

 

 

When I did my zf swap, I did what they call the "Lucky Mod". There was a guy on another board who went by the name Lucky, and what he did was take the dual mass flywheel apart, take the guts out, and then drill all those holes in the center through and bolt it together solid. And then go buy a clutch disc with springs in it.

That's what I did, been in there for years now, but it was very noisy, more noisy than the conversion kits from what I gather. I tried the straight 30w motor oil, don't do it, you can't shift the trans in the winter. I then tried 10w-30, better but still a little stiff in the winter. What I did notice was if I lightly pushed on the throttle at idle to raise the rpms, the noise would pretty much go away. So I went out and raised my idle speed and it helped tremendously with the noise.

After that I noticed when the engine and trans were cold, it was more noisy, and after it warmed up, the idle would be a little higher and the noise would go away. I had a theory, so I went and put the original auto trans fluid back into the trans. That helped get my shifting completely back to stock and sure enough, the thinner oil warmed up quicker and the noise went away quicker.

Each truck is different, how noisy the trans is depends on how smoothly your engine idles. If you want to experiment, lightly put your foot on the pedal after it's fully warmed up and see if that helps get rid of any more of the noise.

 

 

It's whatever you prefer, I used my old auto column. I took the cluster out, took a black piece of tape and went over the PRND321 in the dash to cover it up. I then went out under the hood and took a piece of wire and tied the shifter lever up. That keeps it in park so you can turn the key to start it. I then went in and drove that pin out and took the shifter lever off.