There are tons available...

FYI, Sweptline series trucks were built between 61-71.
The 61's had a special "Dart" grill.
62-early 65's had dual headlight assemblies
late 65-67 had the "pie-plate" front headlights
68 had a 1 year only hood that resembled previous years but shared a grill with the 69's.

69-71 had the muscle car style bulged hood
70-71 shared a grill like in my avatar pic.

You may want to hit up the DTA ... tons of guys selling Swepty trucks/parts. You can browse thousands of Sweptline pictures and see what's available.

www.dodgeweptline.org

 

aye yeah that pretty much sums it up. and the 3/4 ton's had a trusty dana 44 front and dana 60 rear.

however here are your engine choices:
(correct me if i get something wrong)
61-66: 170 and 225 I6, and A-318 poly. (also there were 50 Custom Sports Special trucks made with the HP package which included bench seats, auto transmission, and factory tack in the dashboard - and the 426 max wedge engine. (i think this was only available in 64-65) (those trucks are RARE AS!)

now things got a lil better engine wise in '67.
67-71: 225 I6, LA-318, B-383 (2bbl 9.2 compression 383 - i think same as the entry level chrsyler cars that would come with the grunt 383. but i still think those 383's had a steel crank though - and decent heads.)

transmissions are the NP-420 4spd in 61-65. and the NP435 from 66-71 and every truck after that) - and the a 3 spd manual on the column for d-100's and w-100's.

i think the only auto transmission was the 727.

all trucks had 4 wheel drums so it might behoove you to get a 70's dana 44 or dana 60 for ur front axle.

my truck is a d-200 converted to 4x4 using a NP-201 transfer case and a 71-72 series chevy K20 dana 44. (hella weird but at least the pumpkin is on the correct side)

 

well the strength difference depends on the inner axleshafts. i didnt have about this until i finally got around to replacing the passenger side axle shafts that the previous idiot owner of my truck had broke. My axle shafts used 1/2 ton U joints and i thought they were like that for all dana 44's - but apparently theres beefier 3/4 ton axle shafts available that come with a stronger 3/4 U joint.

I know that certain K20 chevy trucks used the beefier axle shafts. Not sure if dodge used em or what years they had them in their dana 44's. But when i went to my trusty 4x4 shop in sacramento - much to my surprise i found out that my front axle was from a chevy truck - and that even though it was a 3/4 ton axle - it had the smaller axleshafts. so he gave me some used axle shafts from some chevy truck that measured up to mine and they had a much bigger diameter and he gave me the bigger U joint for free - (did what he called the "starving student" discount)

and thats works perfectly for me because the shorter shafts are more likely to break...