To swap in an Isuzu 5 speed here is what you will need:
Isuzu 5 speed (duh!)
Isuzu shift and select cables
5 speed shifter
Clutch and pressure plate for 4 speed or Getrag (I used Getrag)
Throwout bearing for Isuzu
Shifter console trim plate with the 5 speed pattern on it (Rodney Dickman sells a sticker to do the same thing.)

The 4 speed slave cylinder will bolt directly to the Isuzu bracket. Use the VSS and the driven gear from the 4 speed. On the 84 and 85 4 speed cars, the reverse light wiring has to be run from the console to the tranny switch. On the 86 cars, the wiring is already back there by the VSS, just plug it in. The axles are the same on all manual trannies, so they will go right in. Fill the 5 speed with either 5W-30 motor oil or GM (Pennzoil) Synchromesh (STF) ONLY - DO NOT use gear oil or ATF.
The only thing you have to watch out for is the throttle cable at the throttle body. The Isuzu cables will interfere with the throttle at that point and cause a stuck throttle (NOT GOOD). I zip-tied mine to the crankcase vent tube and ran them under the intake tube. It's a tight fit, but it works and looks stock.

A few things to note:

I had the flywheel resurfaced and installed it without shims. I would recommend using a shim equal in thickness to the amount of material removed from the flywheel ONLY if they had to remove a substantial amount (maybe .025" or more.) I DO NOT know where to get shims.

Inspect the clutch fork. They can get deformed and pitted and generally chewed up if not properly cared for. If it looks bad, it will have to be replaced.

Inspect the bushings for the clutch fork shaft. If they are worn, the clutch won't disengage fully. The Fiero Store sells the bushings and Rodney Dickman sells the tool needed.

Unless the slave cylinder is in grade A #1 Government inspected tip-top shape, replace it. I used the AutoZone cast iron replacement. As far as I'm concerned, it's the best. Cast iron is a much better material for this application than a steel tube. Trust me on this one. I do know what I'm talking about.

Make sure the Master cylinder is good. 'Nuff said on that.

Make sure the pushrod (banjo) at the pedal is straight and the loop is up. Make sure there is no play at the bushing. I used Chrysler door pin bushings from HELP! To tighten mine up. I also used a 5/16-18 coupling nut and to hex nuts to make my pushrod adjustable to adjust pedal height. (1 - 1-1/2" higher than brake pedal) I removed the pushrod, straightened it (I cannot believe how badly bent these things get), cut it in half, threaded both ends and reassembled it with the coupling nut using a hex nut on either side as jam nuts.

Get a steel pedal. If you have an aluminum (factory) pedal, it's bent. If you just straightened it, it will bend again. If you can't get a steel pedal (the Fiero store is supposed to be releasing a repro soon), straighten your bent one and wait for the steel one to become available. The part that bends is the U-shaped piece the banjo attaches to.

PM or email me if you have any questions.

------------------
"Its a Fiero thing... Heck, even I don't understand!"

Timothy E. Smith
1986 SE V6
1984 Coupe
1996 Ford Probe GT
1999 Chevrolet Silverado Z71
1975 Chevrolet ElCamino SS

[This message has been edited by tesmith66 (edited 08-19-2002).]