William,

I bought mine from Discount Tire Direct for $145 each and free shipping. They come in two widths 8" or 9.5" and two different offsets, 20 and 35. Which works out to be.....

18x8 20 offset = 5.29" backspace
18x8 35 offset = 5.88" backspace
18x9.5 20 offset = 6.04" backspace
18x9.5 35 offset = 6.63" backspace

Hear is one I really liked, Titus looking through the wheel register.
http://img171.imageshack.us/img171/7363/img0065fq9.jpg

A few more of the back wheels.
http://img171.imageshack.us/img171/7186/img0068mf1.jpg
http://img171.imageshack.us/img171/5499/img0069ic9.jpg
http://img171.imageshack.us/img171/4200/img0070ok7.jpg

Here is a shot of the hydroboost.
http://img171.imageshack.us/img171/1331/img0049an5.jpg

Hear is what I made too mate the T56 to the pontiac motor.

Adapter.
http://img171.imageshack.us/img171/9171/img0051wf2.jpg

Spacer.
http://img171.imageshack.us/img171/9331/img0056ca0.jpg

Modified Bellhousing to clear the starter.
http://img171.imageshack.us/img171/3972/img0053wn5.jpg
http://img171.imageshack.us/img171/4193/img0055lh0.jpg

The abonimation of a cross member that I made and I will be remaking.
http://img171.imageshack.us/img171/159/img0057bj2.jpg

Do you guys think I should grind the welds down on the back wheels that were widened or leave them?

Jimmy,
Grinding the welds down may affect their strength- I'd mount a tire on the rim and see if it balances with the minimum required wheel weights. If it doesn't you may have to have a machine shop cut the welds down on a lathe.

Nice work on finding a low-cost 18" rim and low-cost solution to finding a 12" wide rim for the back. A '69 Bird and cute kids- what more could a guy ask for?

Geno

Small update, I continued to work on the mini-tub. Here are a few pictures of the progress.
http://img410.imageshack.us/img410/6416/img0077aj7.jpg
http://img410.imageshack.us/img410/9428/img0078pr6.jpg
http://img410.imageshack.us/img410/1568/img0079em0.jpg
http://img410.imageshack.us/img410/9283/img0081zp0.jpg

Hey Jimmy, I'm also in the process of building a 69 firebird and im looking to mate a t56 to a 350 pontiac block. So my question is what type of t56 do you have, a lt1 version or ls1? I might be able to buy a lt1 style t56 soon and was wondering if it would work with the modification that you did. Thanks

BTW... awesome bird

Thanks!

I used the LS1 version for my build not sure what it would take to use the LT1 version.

Keep me posted.

Chris