71 K10 towing limits

[71RULES!]

Hi gang. I have a 71 K10 Short Step that I'm restoring. It's coming along, although slowly

My question is to solicit opinions as to how to proceed with an issue I am struggling with.

This truck has a homebrew hitch that is way overbuilt. I would guess that it would rip the frame out from under the truck before it gave way.

I also own a boat that is quite heavy. The boat itself is around 5100lbs, and the trailer is 1700lbs. So I'm looking at 6800lbs if I don't pile a bunch of stuff in the boat. I know this SHOULD require a 3/4 ton, but I've seen many 1/2 tons towing big heavy trailers. I'm just wondering if I might be able to do the following:

1. Take the turbo 350 out, and overhaul with HD guts and shift kit.
2. Put on some kind of rear load assist springs such as helwig overloads.
3. Setup a load compensating hitch for this rig.

Any comments are welcome. I have a 2001 Dodge 3/4 ton diesel 4.4 that tows the boat like a dream. I am thinking of dumping the Dodge, but still need something to tow the boat with. I'm not a Dodge guy, but that truck does tow like a beast.

Thanks in advance for any replies.