I have a 1 ton 52 chevy that I will swap in a 4-53T from my 1 ton 73 chevy.
The 73 got the Diesel in late 73 and has had about a half a million miles put on it, 450,000 before the first rebuild.
It has a turbocharger as well as the required supercharger and should put out about 175HP at 2500 or 2800 rpms.
It also has a Jake brake.
If any one wants the left over 73 pickup after I remove the engine let me know, I will probably drive it for a year or so before I pull it, but if you make me a good deal I could pull it sooner.
I have seen the aluminum 3-53 engines and considered one for a while, they even come with a version of the SM420, just a different cover. But from what I have heard they were one time use throw away engines with the alluminum blocks. But I suppose if the price is right and you had a few it would be worth it. Just don't try to make much HP or it won't hold together.
I have been planning this swap for about 3 years, and in my oppinion the 4-53T is the best choice for a Detroit in a pickup. Some people say it won't be worth it, but I like the idea and it will be different and fun to play with, and loud, but with good insulation in the cab and a nice muffler it should be driveable.
Grigg