[SS Tim]

OK lets start off like this.
Are you wanting to replace the entire external ram system with a later integral steering box?
Like Tim confirmed there is a frame mod required without using spacers.

Are you looking for a replacement box for the existing system?
That box is as far as I know a standard manual steering box.
A quick look through the parts manual shows one part number for 67-72 C10-30 series trucks and a different for 68-72 C10-30 with power steering.
It would appear that the same box is used for both power and manual in 67 C10-30 or the power application box was not serviced.