I had 20 minutes before heading to work this morning so I completed Hart Rod's gas strut conversion on the liftgate/hatch (Original link to his conversion here:
http://67-72chevytrucks.com/vboard/s....php?p=6307193). It was so easy, once I had the correct parts, yet very satisfying.
The key was to get ball studs with 1/4" studs on them (and 1/2" length). I found them on Amazon for around $11 (for 6) and they arrived yesterday. I had previously ordered two 30lb gas struts which had 10mm ball sockets, but the studs that came with were 3/8" and didn't fint into the holes. Rather than tap new holes, I decided to find substitutes.
I am a little concerned about how thin those 1/4" studs are, and the fact that the hatch is now supported by one stud on each end versus the two screws (on the brackets). In fact, one stud snapped off in the upper hole when I didn't have it screwed all the way in and the hatch accidentally closed jamming the strut and shearing the stud. I will be keeping an eye on them for stress/wear.
The reason I ordered 30lb struts was because on another thread someone had actually weighed the hatches and they are estimated to be around 51-52lbs (and at about $14 a piece they are cheaper than larger struts). I was very pleased to find that estimate to be a good one because one strut was not enough to support the hatch but two were absolutely perfect! They are also thinner than larger struts so they fit into the jamb without rubbing and I think they look more balanced when the hatch is open.
The opened height is a little lower than it was with the stock braces, however, I do have a a few more inches I can gain if I swap the lower studs into the top holes of the opening (as can be seen in the final pic). If that is not sufficient I can look for a slightly longer strut, but I don't want to go to the 70lb struts that Hart Rod originally used. I want to be able to close the hatch sometimes!
I highly recommed this conversion for its low cost, ease of implementation, and vast improvement over the original tech!!