An 85 Celica has a 22R engine in the US (othe countries differ).
The 7M-GTE will fit your 85 GTS but it is a tight fit and will definitely handle badly (too much weight up front).
It might also require shifting the radiator forward (shift weight even further forward).
There are bellhousings to allow your old gearbox to fit the 7M but the 7M-GTE would break it too easily, so you are also up for a new gearbox and fabricating gearbox mounts.
The Supra from the same year as your Celica has a 5M-GE, which can be uprgaded to a 7M-GTE much easier than your car because it was designed for the M series engines.
The 3T-GTE suggested by TubRog05 is an excellent choice but it may be hard to find one in the US.
Toyota used Celica 84-85 coupes with the 3T-GTE (modified) for the World Rally Championship.
Easy choice would be to add a turbo to your 22R-E.
Use the manifold from a 22R-TE.
Add an aftermarket computer because neither the 22R-E computer or the 22R-TE computer will be able to handle it.
www.lcengineering.com have the bits you need.
Change your 22R head for a 20R head to raise the compression ratio.
See
http://ourworld.compuserve.com/homepages/stepho/eng20r.htm for details.
Again, LC Engineering have all the bits.
- Stepho