Ok Good news. I'm nearly done with my rear end swap from the 85 posi 9 bolt going into my 87 with the open diff. Not easy to do when all you have is two jack stands and a small 2 ton jack. Anyhow, next big project as I have said is going to be swapping transmissions (Auto 700r4 is coming out to be replaced with the T5). In my last post I asked about the vss and I was told not to worry about it since my engine isn't stock. My question now is will I be able to take the tail shaft off the 700r4 and put it on the T5? Reason I ask is because the speedo on the 87 is computer driven but the 85 isn't. I know I will have to swap the gears to get the right speedo reading since everything is being moved over. Thanks for the help and understanding guys. Transmissions aren't my thing.

The tailhousings are different and will not interchange between the automatic and manual. on a T5 the newer tailhousings have a different speedometer drive location and the gear is replaced with a different ring. You can replace the tailhousing and gear from a newer T5. I could use your gear and speedo drive if you do replace it.

However the best for you would to buy a converter that hooks the mechanical drive to an electric speedometer.

AH you mean a universal VSS!!!!

I happen to have one of those for sale.....
I have a universal vss i was using on my bird. It has provisions for both electric and manual. PM me if interested.

You need an 86-89 firebird VSS for a T5 car and correct gears.

You might want to get rid of the 2.73 rear while you're at it, for a ratio more tractable with a stick trans.

OR a universal with...


Worked perfectly with my 89 GTA dash electric speedo. I have the vss, the yellow buffer box and the computer for sale. I personally used the vss with a Dakota SGI-5c to drive the 89 gta speedo.

I'm putting the rear end out of the 85 in my 87. That one has 3:27 gears. Jupiter how much are you selling for? I also have a whole lot of other parts that are going to be for sale as well. Like the entire stock rear suspension from the 85. control arms shocks springs and all