The old International has become a popular truck, and the SBC chevy is probably the most common power plant for any swap. I'd just start using Google or some other search engine, and you will find someone else who has already gone through most of the pain.
You may have to consider swapping transmissions also, since adapters can sometimes get quite expensive. A GM TH350 is relatively inexpensive, easy to find, and very reliable. The TH700R4 is also good because of the overdrive, but will cost more. If you want to stick with a manual trans I would look at car transmissions, since the truck 4 speed is usually a 3 speed with a super-low first.