Are you planning on dropping it? and how much?
You can go aftermarket like POL -
https://www.performanceonline.com/60...pension-parts/
A 65/66 will have a better frame mount for the panhard bar IMO for clearance if your dropping it along with the POL bar.
There is one other company I used previously, they make a great product but it hits the frame on the P-side when dropped:
http://67-72chevytrucks.com/vboard/s...1&postcount=31