Sounds like the first thing you need to do now is do some measuring with a mic, both on the end of the 440 crank as well as the input shaft of the T56 Magnum. You've got to mic the diameter that you have room for on the end of the 440 crank you're using. The input shaft to the T56 Magnum is a Chevy size as purchased, so you're going to have to use one of those pilot bearings, or else you're going to have to machine the end of the T56 Magnum input shaft to whatever pilot bearing you want to use. I think what you're running into is that your end of the crank size is too small or not bored in far enough for this setup to work as bought. But you're going to have to measure this stuff yourself in order to know -- there's no other way anyone here can give you a part number and everything will magically work and clearance right out.

Whatever you do, keep the grinder and sawzall away from the end of the input shaft on the T56 Magnum. If you go that route of machining this down, do yourself a huge favor and have someone that knows what they're doing (it might be you, I'm just not assuming anything.....) take the input shaft out of the T56 Magnum case so it can be machined properly. You can also machine the end of the 440 crank, but this needs to be out of the block to do and mounted in a lathe too, so it's not a simple deal either way you do it if you want to do this right. Either way, it sounds like you need to measure for clearance both in and out as well as diameter sizes to get this to work correctly for your situation.