Looking for some advise

First Hello, First time posting here, been reading over some of the other forum posts and thought this would be a good place to ask my questions.

I have a project in mind and wanted some advise on it.

First off the Truck and its spec's.

1990 Dodge W150 4x4, (Ex Forest Service  Rig)
GVWR  06300 Pounds
Gawr Front and rear are 3280 / 3600
360 V8 engine 5.9L
Manual 4 speed Transmission with Granny Gear
3.55 or 3.54 gear ratios in the axles.
Dana 44 up front
Dana 60 in the rear

Modifications include a 12k winch on the front, and rear disc brake conversion. rv cam, and a highflow intake. Chromolly shafts in the rear axel but not the front.

Its a fairly nice truck for as abused as it is.

(All weights are provided via the local truck scale)

The truck Fully loaded with me the wife and our daughter, full tank Bed full of junk etc,, is about 3200 Pounds.

Question #1 If i did the math right this means my payload capacity is around 3100 Pounds right?

Further on, The wife and i were browsing the internet and came across the Turtle V expedition truck, After we got done drooling, we started crying as our budget would never allow a truck that Nice, Then we got thinking. Most likely stupid thinking i am sure lol.

We have a 8' cab over camper that was given to us, we were going to use it as a chicken coup but no longer have the chickens. When we brought it home the truck handled fine at 55 on the high way but i have no idea how much it weighs.

it has a full bed over the cab, a kitchen, dinette, and a closet, no bathroom, and just a fresh water tank for the crummy little sink.

We were thinking about taking the bed off the truck and bolting the cabover to the frame. if i keep at or under the GVWR of 6300 we should be ok right? I understand that 6300 is the max amount the truck can handle and i should not ride at that number. but How close can i get in reality?

I Do not plan on doing any hard off roading, mostly brush and field type stuff or along the lake.

My initial thoughts were that i could gut the cabover, remove the bed, bolt it on see what it weighs in at total, then start adding features and loading equipment etc till i hit the 6000# mark on the scale. leaving 300 for a safety margin?

We cant afford a new truck, and we cant afford a new pop top camper. I dont know what this camper weighs as is but 4 fat beered up guys can pick it up and load it into the truck.

Anyone want to chime in? Thoughs, Idea's, Storys Good or horror?

My other thought was welding up  a base frame and then building a shell atop of that and making a custom cab over. My friend is a carpenter, says its easy to do with the 1x2 studs, Im a welder by trade.

My ex wife gets all my money...  Im just trying to give my family something a little fancy that me and the wife could take out on the weekends and such and "Pretend" were special in :/  Go easy on me please

I would start by just loading the camper-shell and have it weighed.
Then you can see what ypu have to work with.

There are too many variables in component weight for what you may want to put inside
to even guess at total weight. Just start a search and make notes on items and weights.
Leave room for food, water, clothing, etc that you would want to take.

You have a truck that should hold up well. Very strong components.

It can be a fun project, especially being able to make it your own.

You'll save about 300 lbs by removing the pickup bed, but instead of setting the camper directly on the frame I'd think about slicing the bottom box off of the camper and mounting it on a box that matches the camper's outside dimensions.  This would open up the inside space instead of restricting you to the present 4' x 8' floor footprint and you might gain enough space to install a decent size porta-potty closet.