Need Single peace drive shaft 80 c10 4 speed

[80c10]

As the title says i have an 80 c10 and it is currently a straight six with a two peace drive shaft with a farm truck 4 speed (low gear). i am planning on putting a 454 about 500hp and tq with a muncie m20 and i want to convert to a single peace drive shaft because i dont think the double can handle that much torque or am i wrong? The problem is that i cant seem to find any place that sells 80 c10 single peace drive shafts. So if anyone knows any places that sell them can you please post a link to there website or a phone number to get a hold of place that makes them. Thanks any help is good help !