Not all 3rd gens are created equal.  For those that know 3rd gens know what this car represents.  Those that do not, here is what makes this car special and why you find it in my collection;

 People debate what year 3rd gen F-Body is the best.  Although that debate can go up and down and have different answers for a lot of reasons (my personal opinion is 87 on 5.7 Iroc and 89 on 5.7 GTA), but when it comes to the factory convertible Iroc, 88 is the simple and final correct answer.  Why????

  When you talk about these cars, they are muscle cars. And we can go back to the 60s and see what car is valuable now and its usually based on its performance package combined with rare options.   Muscle cars desirability in later years is usually about how much muscle and rare performance options that car had as it left the factory new.  For a convertible Iroc, it is very rare to see a 5 speed in the first place, so they are certainly a collector contender of any year. The convertible cars were a good bit more money than a coupe new, so loading one up could really get you up in the money dept, so very few were ordered for that reason as it was too close to a corvette in price once it was all laid out.   Many more "adults" were the purchasers on the convertibles, and the automatic was more attractive over a stick to those just wanting a cool car vs a hot rod that is better left in a coupe anyway.  There never was a 5.7 motor offered in any 3rd gen factory convertible, so the hot 5.0 with the stick was all the performance you could get... and it was only for one year and it is a direct contender with the 5.7 car when packaged like this.  88 is the highest HP convertible of all the 3rd gens and that power only came if the car was ordered with the rare G92 option in a convertible.  87 and 88 were the only time the G92 package was offered on a convertible but 88 has the hotter engine on the stick cars.

 The 5 speed G92 is a lot more entailed than just a transmission or gear ratio on these cars.  The engine itself is different vs its 5.0 automatic counterpart  BUT they did not categorized it under a different RPO, and for that its so hard to track after the fact!  The engine is the LB9 TPI motor rated at 195HP.. But if the car was G92 5 speed it had 225HP.  Changes in the same RPO engine from auto to stick are the heads are different, the cam is different, the exhaust system from the heads back is larger and shared with the 5.7 car.     Then you have the transmission.  This is the what they call the world class T5, and was only used on the 88-92 higher horsepower G92 5.0s.  It is stronger than the previous years and was carried on to 1992 and had a .73 overdrive 5th gear vs a .63 on the other versions.  Then with this package comes more, the Kc4 oil cooling system which is designed to keep your oil cool as you race the car!  You probably will not see any convertible past 88 with that and in 87 and 88 is rare to begin with. I dont think it exists actually after 88 in a convertible.  Then the 145MPH spedo.  Try and look for any convertible that has that to begin with.  If you see one, its only 87 or 88 G92 cars.  Then rear disk brakes (J65) are part of this G92 package, and G92 is of course rare rare rare on a convertible and only available 87-88. Remember there are no G92 cars after 88 on the convertible.  Another part of the G92 is the gear ratio, and that is 3:45 (GM3), that is housed in the larger ring gear Borg Warner (Australian) differential.  5.0 auto got the smaller housing and often 2:73 gears.   After 88, you will not see any iroc or 3rd gen convertible with J65 rear disk brakes... at least as it left the factory.  89 and 90 do not have the G92 option on convertible and they also have less power because the G92 was dropped on the convertible. Remember unlike the 5.7 liter car which had 230 to 245HP from 87 to 92, the G92 option on the manual car is engine based and the non G92 motor is 195HP vs 225HP.   

 So to make it a little more clear, 88 is the highest HP engine you will see in an Iroc or 3rd gen convertible with 225. Whoo hoo right!  But its rare and the car will do its advertised 149 MPH with pretty respectable acceleration.  Only one year 88, and only a few convertibles made with the G92.  Now lets not discount 87s with G92 as they are rare and deserve credit, but the difference on 87 and 88 are the engine is more powerful in 88 on the 5.0 LB9/G92 motor and the T5 transmission is the world class that was new to GM in 88.  Also I have not seen a 5 speed convertible with the bigger differential other than in 88..  It may exist, but the few 5 speed 87 convertibles I have ever seen have the 7.5:" rear diff.  88 has the big one shared with the 5.7 on the convertible 5 speed G92 car.

A lot to think about there and I still have a hard time with the vast differences in what most people see as all the same car.. and that comes even after owning over 50 of these 3rd gens in my life, racing them all through the 80s, working on them constantly, and networking with other owners to gain exposure to 1000s and 1000s. The uniqueness of this configuration on a convertible really only came to me 20 years later and I took my time to find the best that ever came about.... And its not brand new, but its good enough and all I could find!    I am sure there are other things I have not figured out yet too on these 3rd gens!

 How many Iroc 5 speed 88 cars were made???   Well no clue.  Wish I knew and possibly one day that data will be compiled on these rare options but I will throw some percentage logic based on what we do know as fact; 

There are 96275 Camaro/Irocs made for 88 (nothing rare about an 88 camaro)

There are 3761 Iroc Convertibles for 88  (getting pretty rare here)

There are 5252 G92 cars for 88  (pretty rare here too)