Disc brake conversion question

I just finished writing this and noticed i went off topic a bit for the sub forum . Move if need be.
So I have 76 dodge dart sport with a 223 3.7 slant 6. It has drums on it so it's an early 76 as in 76 they started changing to disc for all. Anyways there is a swinger that has disc brakes at the junk yard that has disc. The upper and lower control arms look the same. Are they tho. Do I need to take them as well or just the spindle forward?

I got the dart in a trade for mechanic work. Already put a bit of cash in it. New tires, upper and lower ball joints, inner and outer tie rod ends, power steering gearbox and pivot arm, waiting to pull the motor before I replace the passenger side one as the bolt gets stopped on the motor, shocks in front, non adjusting coil over shocks in rear, belts, hoses, front rubber brake lines and the metal ones that connect to the drum caliper, rebuilt carb, new distributor, dis cap and rotor, spark plugs and wires, I started 3 in pipe where the cat used to start at with a 40 series flowmasters muffler i still have to dump it to the back of the car. Right now it stopped about a bit more than a foot from the axle was think of splitting it and running 2 2 1/4 inch pipe out the back. 3 inch looks like it will be a ***** to make it under there right without future issues. Clearview gas filter, upper control arm bushing in the process will finish in the morning, fixed the auto choke spring on the intake manifold, waiting for a new choke diaphragm.
Still need to dial in the idle but I think it will be fixed with the new choke diaphram.
I bought a chrome valve cover for it but the new cover doesn't have a hole for the off valve.
The previous owner stripped all the smog equip. I saw there is two diff heads one with and one without smog. What is the diff.
Seems to be that my air filter has gotten dirty pretty fast. Much faster than it should have. Thinking I'm betting to much blow by and have the piston ring set already but I'm waiting til I have enough to matching the block and heads of need be.
If I get it dialed in mostly right other than the blow by and it still lacks power climbing the mountains I'm gonna replace the cam and lifters along with the exhaust manifold and put some hookers on it. Already planning on getting a new intake manifold. If I can find one cheap enough at the junk yard with a 2 barrel I'll be happy. If I have to order a new one I'm going for a 500cfm 4 barrel.
Paint and interior will come later when i have the time and money to completely strip down the car and get it all done. Then the interior im dreading cause sewing is so time consuming lol. Im hoping to find some buckets i like in the right color so I have less work lol.
Paint will be a bright green like the snap on took boxes I'm hoping to find someone to airbrush some purple ghost flames on it I can trust. Motor will be purple and chrome maybe. Interior pure with green accents and green led interior lights and underdogs and seats maybe.
Stereo will be started once motor is tuned mostly factory stock. Rockford fish are 6 in I'm hoping to put I front doors if the will fit. 6×9 in the rear. Local shop has a sony deck running 400 watts. No need for an amp for my interior. Still contimplating the sub/s ill be putting in. If i had the money and i dont rockford has some infinite watt speakers. Super wicked. I may take the Rockford out of my Van and put into it and put some kicker comps into the Van to match the resits system.
Front windshield will get replaced this winter sometime as well.