The variations were MANY. I have quite a few sets myself and have compared them to each other and other that I've seen posted on this site over the years as well.
I don't know all the differences but here a just a few things I've noticed.
On the original late-84 (didn't appear on bikes until 85 however) and early-85 bars the cross bar was a little higher than the 2nd run somtime in early 85. The knurling on these crossbars was all solid (unlike the bottom set in the picture above which has a break in it). The rake and rise seemed pretty consistant during this time unil maybe very late 85 where they transitioned to the next versions.
The early-86 versions (or around there) really began to differ in almost every aspect. Rake, Rise, Length - all seemed to differ from one set to another. Also during this time the weird tapered tubing began to appear but only seemed to come on complete bikes for some reason. This is where the bars were severly smaller beneath the cross bar and then drastically tapered back up to full size (7/8" or 22.2mm) at the stem clamping area.
The original bars that came on the Sports & Masters were all stamped "Haro SAE 4130" on the area where the left handgrip would go. The one thing I'm not sure of, is whether the original FSTs ever came with STAMPED Haro bars. Can anyone confirm this? I believe all the later (86 on) versions of bars that were on FST / FSX's were all hi-ten steel NOT chromoly since these bars were never stamped.
Aggregate Ranges:
Length 26.25" to 28"
Rise 4.25" to 5.5"
Rake - not sure how to measure
Sometimes I feel some of the differences were just quality control (also supplier changes) while others were bona fide intended differences (obviously cromo vs. hi tensile). Remember in 85/86 Haro couldn't keep up with demand.
I could add more, but this is enough for now I have (*&^ to do right now. Maybe more later.
BTW - These are NOT Haro bars in this auction........
Ebay Auction for Haro bars BUT, for the record I'm not sure the seller isn't just un-informed about them.