[shifty]

I created a decent thread with pictures on how to do the HEI upgrade over in the FAQ forum. You should check it out.

Power brakes - simply add a booster on.

Power steering - you'll need a power steering gearbox, both hydraulic lines, a power steering pump/resevoir with the correct pulley on it, the pump bracket to mount it to the block, and the pitman arm for the power steering gearbox is different, so you'll need a new one of those with the rag joint as well, if memory serves right. Chances are you can buy a whole used setup from someone at the forum for around $200. Visit the parts forum for more information on that. Vendors like 'teeitup' and PICKMUP (sp?) usually have lots of salvage parts on hand.

Lowering you can use springs for a quick 2" drop if you don't have leafs in the rear. Otherwise, lowered springs in the front and blocks in the rear are possible. You could always cut or heat the springs with a torch also, but ... you lose some of the necessary resistance on the spring when you do either, which will give you a bouncier ride in many cases. The best possible suspension and handling upgrade you can do is adding a swaybar. You'll be amazed by the difference.

As for A/C, you might as well go aftermarket. If you didn't have A/C at stock, you probably do not have the vent hole above the radio, nor the ones on the dash next to the glovebox and the gauges. The only vents you'll probably have are on the floor and in the top of the dash (defrost). I have the same thing in mine. There are lots of aftermarket solutions. Here is an install of Vintage Air, which is highly recommended by lots of people:

http://67-72chevytrucks.com/vboard/s...75#post1310375

There are several very informative threads floating around here on the subject. Expect to drop about $1k-1.5k on the aftermarket air. It's a lot colder and easier to take care of and get recharged than the stock air from the 70's was.