I've been running these for years on my '86 Westy without issue.  I have the VanCafe lift springs so the length is right.  But I've not experienced any problem at all with fitment to the shock mounts.  They go right in.  Not sure if the '84 is different or not.  I never run more than 15 psi in mine, and they work just fine.

Keith
 ------------------------------
 
 Date:    Sat, 21 Nov 2015 17:13:41 -0500
 From:    Michael McSwain <michaelmcswain@GMAIL.COM>
 Subject: Gabriel Hijackers on an 84 Vanagon?
 
 Recently purchased a set of Gabriel Hijackers for my 84. I
 saw various
 posts saying that they would fit a 2wd even though all the
 auto parts
 places say it fits synchro only. Well now I'm having trouble
 getting them
 to fit into the upper and lower mounting brackets on my
 van.  There's a
 steel sleeve that goes through the bushings. It doesn't seem
 to want to
 come out and it's a perfect fit for the mounting bolts.
 Problem is that
 it's too long to fit into the mounting brackets on the van.
 And even if it
 would come out, the resulting hole through the bushing would
 be too big for
 the mounting bolt.
 
 Anybody have any experience with this?
 
 --
 m.