I haven't found a rebuilt 4-53 that cheap. ARSCO has em on ebay for $3500 with a $1000 core. You can get a used one from Adelmans for $2500 and can probably get the brackets and accessories for that price if you are real nice.
I wouldn't put an agricultural 4-53 where a truck engine needs to go.
Don't forget rebuilt units are usually just long blocks, so you'll need an air pump, alternator, brackets, water pump, intake, exhaust, turbo if its a T. Oh and then you need the bellhousing or adapter and the flywheel or flexplate to hook it up to your gm transmission.
Diesel swaps are not cheap. If you can live with a 3-53, Adelmans will sell you an aluminum blocked 3-53 with all electrical, bellhousing and SM-465 trans for $1850 out of a military DUKW. I just don't think the 85hp and narrow power band will work for our trucks. Maybe with a gear splitter or gear vendors unit, but that's a lot of cash.
Grigg probably won't be able to comment until the weekend, but he's dropping a 4-53T with a roadranger trans in his truck.
