Can I have your old axles? Why do you want to change 'em? If they're not broken,you should keep 'em. Keep in mind it'll cost you a BIG chunk o' change to get a GM posi front and rear completefor your truck,and if you break anything on the GM axles it won't be much cheaper to fix. If it's about custom wheels,there's a lot of wheels available for it; you might see if Ford 1/2 ton wheels fit. (try one on front and rear-don't just go by measurement.)
Not a lot out there for cornbinders,but there's a few things you can improve. The 392 cane with a 4 barrel intake-that's a good thing. Use a 600 cfm Edelbrock carb;you might have to fine tune the jetting,but it isn't hard to do. I'd also do the Pertronix ignition on it,and dual exhausts,at least 2-1/4" pipes.If you really have to squeeze more power out of it,mill the heads a little and get a good cam for it. depending on where you want your torque to come in,you can probably arrange it here. You'll be wanting low end and mid range performance,Internationals don't handle high revs well.Gut ripping torque is their gig.
Don't expect great gas mileage-they aren't an economical engine,but as long as you take reasonable care of 'em and don't twist 'em over 4,000 rpms,they're amazingly tough and reliable.
See if there's a line sheet in your truck. It's usually tucked into the seat back. If you find one-BINGO! It'll be very helpful in buying replacement parts. IH used parts from so many different manufacturersDelco,Motorcraft,Motorola,Echlin,Holley,Carter,name it) that without the line sheet,which will tell you the part number for pretty near everything installed in your truck at the factory,it's nearly impossible to be sure of getting the exact correct part.
Enjoy your truck,and don't drive stupid.
Speed
