Conversation Between acl9865 and tug captian

Brakes are from a 96 F350 2WD dually. Cut the dually extension snout off and machine that surface flat with the rotor step. Bore a 3.84 hole and drill a 5 on 5.25 bolt pattern. You need to counter bore a bearing boss for bolt head clearance from the inside. This will bolt to the F4-6 hub. I had some plates water jet cut from 3/8 steel. One that is circular that bolts to the spindle as a backing plate the other is the caliper mount. This is inset using 6" pipe 1.75" long. Bosses need to be added to the caliper plate to move the mounting surface outward to clear the slide assembly. I think those ended up at .625" tall. Have drawing for the pieces if you want them. Draftsight is a free CAD download.

Can you share how you did your front disc conversion?

6BT will not fit without pushing the firewall back. The 4BT is easily pumped up. Plan on around 190hp and 475 ft-lbs. Installed the Gillett 60mm compressor and starting the intercooler fab. Should be plenty for the truck. The stock 105 hp worked pretty well

My #1 choice would be to fit the 6BT in the F4, IF it fits. No problem cutting and fabbing new crossmember and transmission members, just refuse to touch sheetmetal. Either way I'll go check out those fluid filled mounts as well!

The biggest thing to remember is the 4BT is big for a 4 cylinder. It has no counter shafts so it vibrates. I went with urethane mounts originally and with the dump bed on my F5 it had a constant banging between the bed beams and the frame. Went to fluid filled mounts and that went away. The 5 speed required cutting the center of the tranny cross member. I welded plates on what I left of the cross member since I still wanted to retain the master cylinder location. I've got a bolt in tube section to support the tail for the transmission. That will make clutch replacement easy in the future.

Seems I can't PM you yet, need more posts. But I definitely would like to get more info on your swap and any issues you faced!