You need a Ford with the 222wb so you can fit the propersize box on the truck. A 16'6" box fits good on a 222wb some guys run 15' box but its a little short for the legal payload of 15 tons.
The 425 Cat is more than enough power for general use start getting anymore power then you break things. You want good gearing instead of big power and too tall gears meant for highway. You definatly want a JAKE a truck without is alot more work to drive plus you burn up brakes faster.
Most Cat 3406s have retarders which are quiet they hold back pretty good I think the only problem I heard of is engine oil takes a beating.
The older Fords mainly came with Cummins like the L-10 350-400 Big cam the 3406 was used more in the LTL trucks. As for working on the engines in the L series with the 400 Cummins shoved half under the cab can be a real
The contractor I work for has a L-9000 with the 400 Cummins shoe horned under the hood. You try do anything on the engine is a PITA because its cramped. To fit the engine under the hood Ford had to tilt the engine to the passenger side to make it fit
The truck steers good and climbs out of places good you do get cooked out of the cab because of half of the engine is in the cab the doghouse doesn't repell any heat. The LT-9000 the contractor has is nicer to work on atleast the engine isn't under the cab so much and its easier to access the parts. The truck is quieter in the cab and cooler too because most of the engine is forward of the firewall.
The LTL 9000 I drove and took my CDL on it steered okay it does have a huge hood.
I would buy a LT-9000 Ford my second choice would be a Western Star the Kenworths just don't turn very well unless you get into the T-800s which are expensive.
As for buying a older International it wouldn't be on my consideration list I work on one and its a PITA. International did some goofy things if you ever had to pull the dash apart on one or try deal with the wiring you know what I mean.
