Your biggest issue with the 3600 truck, in my opinion is the steering and brakes, not an engine. If you've been around the site awhile, you'll have seen plenty of non-original engines between wheel wells.
There are NO front disc kits for the 3600 or 3800 trucks. You'll have to come up with that on your own. Then there is the steering issue. I wouldn't even think about pulling a 10,000 lb trailer without power steering.
The AD trucks were made to haul, not to tow. I would suggest getting a 1960 or later truck if you want a vintage truck with towing capabilities.
Just my $.02
