what is the best replacement for an 1985 305 tpi/throttle body. Ive looked at the bbk 52mm. Is this to much for the 305. only mods will be slp performance runners and upgraded exhaust.1 5/8 headers.

In a few minutes everybody is going to tell if you need to ask about a bigger throttle body you dont need one.
I suggest spending the money on an adjustable fuel pressure regulator and some good air filters like some K&Ns instead.

The regulator and filters would be fine,But my throttle body is junk it needs replaced.

tbair,

(Know a 'gbair' in WI?)

My guess is that you are asking because your TB has seen better days. You can try to bush/rean the throttle shaft on the existing TB, or get a replacement. The BBK would be just fine. It will only admit as much air as the throttle plates are open. It isn't going to hurt anyting at WOT. IT won't make a noticable increase in power, either. Your MAF should read incoming air and trim fuel accordingly.

Yeah if yours is shot then get a new one. I got a BBK 52mm and it works great.

Sorry dont know a gbair.Other than my son Garrett but a ripe old age of 5 he doesnt get around to much. So I dont think there the same person.Is e-bay the best place to buy a bbk?

No, this 'gbair' hasn't seen the short side of "5" for about 45 years.

As for shopping, that's up to you. You might find a decnt one on eBay, or even in the TGO classifieds. Determinimg just how good its condition may be could be difficult, however. There is always a stock TB from a bone yard, but that could be in just the same condition as your original. Whatever you get, make sure it will fit the early TPI.

There is a couple of guys on ebay installing roller bearings and reworking worn throttle shafts. Go to air intakes and type in tpi and search. you'll find it.