I just picked up a 1972 Dodge Dart, small bolt pattern with the factory Kelsey Hayes front discs. The rotors are shot so I thought it might be time to do any upgrades.

Are there any larger rotors available for these spindles like there are for the later Bendix setups? or just better pads or caliper upgrade itself? Not looking for a racing setup, just want to replace it with good stuff while it needs replacing.

those would be SBP. if it is BBP see if it is the '73 up A body single piston slider setup or another BBP type. EDIT SBP also has 7/16 studs & BBP is 1/2" & the KH are 4 piston calipers

You are correct. I was looking into large bolt pattern stuff at the same time I was typing this post and put the wrong bolt pattern. I apologize for my lack of proof reading.

The car has the 5 on 4 small bolt pattern, 4 piston brakes. So now that that is out of the way, are there any good upgrades available?

Early Mustang rotors, also made by Kelsey Hayes, can be machined to fit the a-body spindles and have the 4-1/2" bolt pattern.

http://www.forabodiesonly.com/mopar/threads/using-mustang-rotors-for-4-5-bc.20544/

No apologies needed bro, we're just human. I would get some aggressive pads even if just some parts house "ceramic" pads which'd be a step up & talk to your lathe operator. If your shop owner runs the brake lathe faster it will produce a rougher finish & give more grip but wear the rotors faster (tho I wouldn't sweat that), talk to him regarding that. best bang for the buck would be to do a bed in procedure (Google it) with some aftermarket pads.

Why?

No stopping improvement. and new rotors for the Dart are under $20 each for stock, slotted and drilled are available, see Rockauto.

It gets him the larger bolt pattern with the least amount of work and money. He did mention switching bolt patterns, and the mustang rotor switchover is an option that not a lot of people are aware of so I tossed it in the ring.

What it doesn't provide is larger or thicker rotor options so braking capacity would be the same as with the oem mopar rotors.

No, he did not.

Looking for more braking power in the same lug pattern. The 14x6s with decent tires aren't locking up with the current brakes, I have room for improvement without switching wheels.

You can get slotted and drilled rotors in the SBP, rockauto has them.

Summit has a variety of upgraded pads for it.

Two part answer.
a. Not locking up. Assume this also means not stopping hard, which is why you asked about upgrades. On a wet surface or even a dry surface, slamming the brake pedal should result in lock up of at least one, preferably two or all four wheels. If not, something is wrong, and some investigation will be required.
->As the car is new to you, look at all the pads and shoes - write down or photograph their condition and if readable, the edge code.
->Bleed the brakes, all four corners. This will do several things. One is that it will provide clues about the condition of the hydraulic system. If there's a bad hose or blockage it won't bleed. If there's a ton of rust, a piston or cylinder may be hanging up. Another is that the brake fluid absorbs moisture, so it should be changed regularly (I do every Spring) and this flushes out the absorbed moisture along with any rust accumulation. In my experience, Valvoline's synthetic DOT 3/4 has been the best of the normal (street use) glycol based brake fluids. With it, I seem to get the the least moisture and rust in fluid of the ones I've tried including Castol's LMA (low moisture absorbing).

b. Upgrades Yes there are differences in brake material. There are also trade-offs related to how they achieve their grip. Assuming stock brakes for '72, the pads will be D11 and the shoes 311.

For the D11 pads and 311 shoes, you will probably get higher gripping linings from a high performance manufacturer. Amongst most part store brands the friction rating of the edge code can be used as a rough guide as to which ones will grip better cold and hot. As a guidepost, the Mopar factory replacment pads made by Cycleweld had a friction rating of FF. Accept nothing less for the front pads.

Amongst the more race oriented manufacturers there are a fair number that offer D11 street pads, more limited for the shoes.

Some to consider:
Porterfield RS4 I've been using on both pads and shoes for about a year, 7,000 miles. So far, very good and similar feel under all street conditions. They can arc the shoes to your drum diameter.
EBC Red Stuff Several people on FABO wrote the stopping (presumably grip) with "Red Stuff" pads is very good; also fairly dusty.
Hawk HPS
Rochester Brake and Clutch Not a manufacturer but a shop that can provide a wide range of linings to whatever pad or shoe. Can arc the shoes the drum diameter. Tomquad uses them for his street/track day cars.

Agreed, I would start by opening up all 4 corners for a basic look see. You likely will be able to resolve this without any $$$ upgrades.

PS. The Chrysler Master Tech series has very good guidance on brakes. Some pamphlets cover how they work, others how to trouble shoot, as well as various changes in the systems.
Most are at www.imperialclub.org
located here
http://www.imperialclub.org/Repair/Lit/Master/index.htm

Just noticed that you wrote that the rotors are shot. Not much thickness on these to turn them, but measure and see if it can be done.

If buying new, beware that many (maybe all) the current ones come from the same casting manufacturer. Unfortunately the sand casting is has a lopsided 'hat'. I had this on a Bendix branded set over 15 years ago and read about the same issue on the 'net today from other brands. Soooooo...if buying new, test fit the rotors for possible contact with the calipers and piston boots. The better ones will have been machined and/or come from a different mold.

However, if it does contact and nothing else is available, a shop that does turning should be able to machine it and balance should be better. They can use calipers to check casting thickness to make sure there is enough meat in the high spot. The originals from k-h look like they have weights in the vent fins, so I assume it is possible to balance rotors if really needed/wanted.

^ good info, I had heard that those were problematic tho I was not aware of those issues. I will keep that in mind if I deal with one again.

The Bendix replacement at RA looks to be machined, the Centric not.