what is the best lift to buy for a 1988 gmc k 1500( inches, brand)

Dick Cepek 6.5" full drop. No bull shit knuckle lift is gonna cut it.

tuff country and bds are good companies. RCD is also a great company. I have used the RCD and they are worth the money.

height is up to you and what you want

micky

While RCD is a good company from a product and customer service standpoint, their design lacks strength. A 6" lift kit that only drops the front diff down 4 or 4.5" , is not truly a 6" lift kit. Its a kit designed to allow for stock UCA mounts and alignment so that they dont have to fuck with figuring that all out.

If you like knuckle lift kits that cause you to crank your torsion bars to get 6" than by all means go ahead, or kits that kick your front tires out (called increasing front track width). For a full 6" , strong kit, use Dick Cepek. Hell, you can get 8.5 " of lift with the same amount of crank you would have to use RCD to only get 6".

He doesnt have autotrac - so no need to get a knuckle kit.

do a SAS.... for about the same money that you would put into a new lift you can buy the spring hangers and a ford dana 44 and have a much more wheelable and respectable rig. I have done both the SAS took about a day to intall and has been reliable... the IFS kit was a major headache to install and broke (CV's and ball joints) about every other wheeling trip

I recommend building your own but they do make these kits for your year chevy.
Here's a bolt on kit example: http://www.offroadunlimited.com/ProductCart/PC/viewPrd.asp?idcategory=182&idproduct=156
I know there are cheaper kits too but my connection is too slow to do to much searching for ya... google is your friend.