After you consider the machine cost to prep a traditional 6.7 Cummins block for a deckplate, cam bushings, and 14mm hardware drill/tap, there really isn't a cheaper option than the new Hamilton Blocks.
Hamilton has (3) different blocks available that could work in your application and will not require special one-off studs, etc. The new IFG 14mm studs are holding up great in our test project and based on the 12mm test results, we're fairly confident the 14mm will never have an issue.
The solid comp block is a 4.210" bore 6.7 Cummins replica block that was cast solid with factory spec 250 MPA material. It comes setup with 14mm mains, 14mm head stud holes, and all (7) cam bushings and currently retails for $3999. In my opinion, this is the absolute strongest cylinder wall setup currently available. When deck plated, the deckplate portion will warp and become severely out of round before the solid block portion does meaning, the solid block is arguably stronger/maintains its shape better than a mild steel deckplate.
The (recently released) wet comp block is rough cast (unfinished bores) around 3.840" bore. They have an 0.800" thicker deck built-into the block without changing the deck height meaning the wide part of the water jackets starts about 1.6" down from the deck surface, not 0.700" to 0.800" down from the deck surface like a factory 6.7 block. They come setup with 14mm mains, 14mm head stud holes, all (7) cam bushings, deleted steam port holes, 300mpa material (20% stronger than OEM), 0.080" thicker cylinder walls, 0.080" thicker block outer walls, and then to take it one step further..... Hamilton analyzed all the fracture/failure points on PDD's solid block explosion and they added material in the mid-section of the block at the cam tunnel line which is the weakest point on any cast block after the cylinder walls are beefed up. The water jacket floors were raised up to add rigidity and midsection strength, the oiling passages have revised angles/hole sizes to reduce stress points in the mid section of the block, the structural webs that run down the inside of the skirts and tie into the girdle are enlarged as well. This is the Fort Knox of wet blocks and designed for water cooled 2500 HP applications. These are selling fast and retail for $5900.
Finally there is the most budget friendly Upgraded 6.7 wet block. This is a factory replica 6.7 block with the following upgrades: 300mpa material (20% stronger than stock), 14mm mains and 14mm head stud holes, 7 cam bushings, and they come with a finished 4.015" bore size (5.9 standard bore). What this means is they are like a sleeved down 6.7 cummins block without the machine cost/sleeve cost so you can run a 5.9 bore piston, 4.125" custom piston which is common for the 6.4L "budget builds/poor man's deckplate replacement" etc, or bore it out to a standard 6.7L. This block is designed for 1800 HP with the small bore size and might even do 2000HP or better on a high RPM, low torque setup with the smaller 4.015" bore size. It still has the proper deck height for the 6.7 crank so you still end up with 6.1L engine setup even with the small bore size. These blocks retail for $2900.
My shameless plug....Power Driven Diesel is a master distributor for Hamilton Cams so if you don't buy direct from Hamilton, give us a call, we have a few of these blocks in-stock!