Ok from what Ive heard, Chevy never made a manual IROC or Z28? So how do you make one manual? Im sure that the Vettes of the same year were manual! So couldnt you just get the tranny outta one of the Vettes?

 

The Vette trans sucks. It's that "4+3" thing they had. I don't know of any where to find out what would be involved, because I don't know of anyone who would even bother trying. The later ZF-6 is a better gearbox but very difficult to adapt.

It would be possible to swap a T-5 from a 305 car in there. If you do that, get a V8 trans setup (preferably a whole donor car) from 88 up so you get the better T-5. Or, a better alternative might be to put a T-56 from a 4th gen in there. That's a little more work but you get a stronger trans and a taller OD so you can also use a higher rear ratio.

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"So many Mustangs, so little time..."

 

This is one of those many debated topics. I have heard time and time again that Chevy never put the T-5 (manual tranny) behind the 350 in the 3rd gen cars. I guess they say the tranny will not hold up. However, I have also heard that there were some. It was like a trial run to see how the cars would do. And a few months ago in the local newspaper (Oregon) I saw a third gen for sale that claimed it had the "very very rare" option of a five speed and the 350 stock. I don't remember all the details from the ad, but the guy was asking an arm and a leg for the car because it was so rare.

Even though Chevy said that the five speed T-5 wouldn't hold up, there have been a countless number of people who have swapped out the 305 for a bigger engine and have had no problems with the five speed (with no mods to the tranny either). However, then there are others who have vaporized the T-5 after only a few thousand miles. Luck of the draw I guess?

If you are looking for a nice Iroc with a five speed, 1990 is the year to look for. Chevy put the five speed behind a version of the 305 that came with 230 horsepower. That is only 10 horses less than the 350 of the same year (240 hp). So for the sake of ten horses (that you could add later on) you get a 5 speed to play with. And heck, as far as I can tell (please, someone correct me if I am wrong) the most HP from the factory that the 350 had in the 3rd gen cars was 245. So, if you could ever find a 1990 Iroc with engine code BLH, you have a decent amount of power, and the joy of a stick.

 

friend had a worked up 350 with a t-5 and all he did was spin. but if you want a tranny that will hold up fortes sells a tremec that will take 500hp but its not cheap www.fortesparts.com