installing 883 I have 440source flywheel question

The balance weight you get with the 440 source flywheel is a little bigger (heavier) than it needs to be for a 360 but for a stock engine it probably wouldn't matter that much, just bolt it on and go, factory balance jobs weren't that accurate to begin with. Mcleod sells a balance weight for a non magnum 360 which is a little smaller in size than the one from 440 source and presumably more accurate. You could grind down the weight from 440 source to look like the one from Mcleod and probably be real close or buy the weight from Mcleod and bolt it to the flywheel from 440 source, they both have the same bolt pattern.
Also there are two positions to bolt the weight to the flywheel, one for the small block, one for the big block. If you laid the flywheel on the ground with the four weight bolt holes pointing at your feet the weight will bolt up to the set of holes to your right for the small block.