So i have heard about the double hump heads and how good they can be. Then i found out there are so many different kind of duoble hump heads im not exactly sure which ones i need. So looking for some advise. If you need more info to help then please let me know. This is what i got:

400 sbc(might bore out, not sure yet)
Mild cam, nothing crazy(soon to come)
Edelbrock performer inatke
Edelbrock 1406 600 cfm carb
Long tube headers

According to block numbers, this engine came out of a 75' K-20 Pick-up(if i remember corrrectly)

Are these even worth putting on or should i just keep the stock heads and build them up??

Im not looking to race this car, but i would like to get some HP and TQ out of her. This will be built on the side so i can still drive the car too, so that will be nice.

Thanks in advance.

 

Depends on what your stock heads are. Some are good enough for what you want to do, and some restrict your engine's power. You didn't mention numbers on your head, so I'd be guessing if you should keep them, or swap.
The old "camel hump" heads come in different types. Originally with 1.94" intake valves, and later with 2.02" intake valves. If the heads were never rebuilt, the valves and seats aren't made to run on unleaded gas, but once rebuilt, most builders swap the valves to stainless steel, and install hardened seats.
I'm running old camel hump 2.02's on my 327 Chevy bored .040", with tunnel ram and twin 400 cfm Holley carbs. They have been upgraded for modern valves, and chambers cc'd to match. Mine are the 291 version, and work great with my engine. I bought therm from the local machine shop, completely rebuilt with SS valves, new hardened seats, 3 angle valve job, new guides and seals, for $399 exchange. They charge another $100 if you don't exchange, or $50 if you just give them any old SBC head.

 

Aluminum heads if you ask me--i like the Patriot heads myself Jegs has them for 885 if i remember right for the PAIR--

 

Don't forget that is a siamese block. They have a tendency to overheat if you don't use heads made for the 400 because of the cooling passage holes drilled in them that mate to the block coolant holes. I'm sure there are people out there with more knowledge than me on the 400's that can tell you what heads will work w/o giving an overheat problem.
If you want better performance you can't go wrong with a set of aluminum heads. They out-perform any double hump head made in their flow characteristics and you can get them in a lot of different cc combustion chamber sizes to fit your needs. The smaller the cc is, the higher the compression if you have the valve clearance. A lot of the double hump heads have 64 cc chambers and most of the newer cast iron heads are about 72 cc. The 640 double hump casting has the highest flow rate that I know of with 210 cc intake runners with a 64 cc chamber. Use the 1.94 valves for the best street performance and low end response and the 2.02 valves for high rpm applications (i.e. drag racing).
Good luck on your decision.