It depends on the TB but I've been pretty happy with the new tbs from c-f-m their first ones had issues with the spring being way to weak so it was very touchy at the pedal and the cruise would be on but it could hold a speed it would let of and on to keep speed. problems more noticable on their early models. I enjoy my old one for throttle response but i love the new ones for their drivability.
I would do a LSD but I barely have money for the clutch plus a trans rebuild. I would do it myself but I don't have the tools or experience. The only person that does that I know said he doesn't mess with fwd cars so I have to take it to a shop . I would love to be able to do this and learn more about it.
I have a TB that I just installed along with a AEM CAI and its frickin sweet I love it, so much response and sound frickin rad, unfortunately the stock TB was seemingly designed to choke the airflow, so the differences are amazing. I would just spend the money and get one from CFM I got mine used for 100 and there like $249 got to love craigslist. GET A CAI OR SHORT RAM!!!!!
My advice is to figure out what you're going to do with the car once it becomes a project car, since it sounds like that's what you want to do with it eventually. You'll save yourself a ton of time and money by making sure that the parts you buy now will work with your end goals. For example, don't get crazy cams if you're planning on doing any form of forced induction.
That said, my Ford Racing IIs may be up for sale this summer, if I can convince myself to spend an extra $400 once my engine is finished up.[nutkick]
the 65 mm tb has alot more throtle response. maybe 1 whp.
32.5^2*3.14159 - 27.5^2*3.14159 = 943 mm^2 more area for air to flow through over stock, and in fact, its more than that cause of the shape of the butterfly on the stock one. so it gives you less restriction overall.