I am currently researching for information about putting the rear suspension from a 2500 Ram into a 1500 Ram

And will also look at Front suspension conversion

I currently own a 2004 ram 1500 SB regular cab with 5.7l hemi and would like to get 2500 payload and towing

 

Buy a 2500. More to a 3/4 truck other then suspension.

 

1500 leaf springs are 2.5" wide, 2500s are 3" wide. You would need new hangers first off. You can however swap in the rear axle no problem.

Here are better options:
Get an add a leaf kit.
Add a top mounted helper spring like a 3500
Install rear air bags
Get coil over rear shocks.

As for the front end, if your truck is 2wd you have coils, you can upgrade to 2500 2wd coils as well. If you have a 4x4, you have torsion bars. Our T bars are discontinued and nearly impossible to find new ones, and we have zero aftermarket support. Either track down new ones, or have yours retreated to return them to near factory condition.
You can also get stiff front shocks and crank your T bars to add some height/stiffness up there.

If you want a 2500, buy a 2500. I have been considering an SFA swap but I honestly don't think it's worth it. It would be easier to keep the IFS and convert to the coilovers from an 06+

 

Thank you I do have a 2wd

using the add a spring is that based o my 1/2 ton springs @ 2.5 " 4(4/1)

I did locate a 5(4/1) kit

is the 2500 axle its self much stronger than the 1500

 

Probably, but the frame is still a 1500. If you need a 2500, trade the 1500. You won't be changing any capacities, towing or anything else. It'll still be a 1500.

 

Yes the 11.5" rear end is definitely stronger than our 9.25", I will swap mine as well.

No matter what, it'll still be a 1500 frame, however, we have very strong frames and adding springs will absolutely increase the capacities and such, but it will not make it a 2500.