I probably don't have all the info correct, so apologies in advance ...
84 had a scissor strut on the right side (I think)
85-? had the 2 gas cylinders (about 6" long) which replaced the scissor strut
somewhere around 88 or 89 the short cylinders were replaced with the single gas cylinder lift on the left side and as far as I know the connection points continued to the end of the C4.
You can buy the short gas cylinder lift kit from MAD, maybe Eklers & Corvette Central too. Be advised that the Corvette tax is alive & well on these little jewels.
Or you can go to
Rock Auto and get the Sachs P/N SG430011 for $7.87 plus shipping. You will need a spring clip and washer for each end of each lift and you can find those at Lowes or Home Depot for around $1.00. The spring clip is rather small and I can't remember the exact size but can probably find it if you're unable to locate it.
Installation is rather simple ... compress the cylinder about 1/4" in order to slip it on the connector studs & install the washer/spring clip. Now compressing the cylinder is almost impossible unless you have some type of compression tool. Or you can make it really simple by having a helper or two hold the hood up, disconnect the long lift on the left side, raise the hood slightly while you install the 2 short lifts, then reconnect the long lift and you're done.
Anyway, I just installed two (in addition to the long lift support) and they work great. Let me know how it comes out.
George