Aaaahhh well, back on topic.
Here are answers to some questions that I was asked via PM, I figure other people may want to know as well.
First of all I am not familiar (yet) with the gearboxes codes (I know most of the engines),
Okay well basically...
A K series gearbox (K40 = 4 speed, K50 = 5 speed) is what comes in a KE70 standard, these arent very strong at all. These are also in the AE85s.
These have a cable clutch, which means to convert to a stronger gearbox you need to do a fair bit of mucking around.
A T series gearbox (T40 or T50) is what comes standard in the AE86, and also is the weakest/smallest gearbox available for the celica! Which is good. These have a hydraulic clutch setup. People swap these boxes into AE85s and KE70s etc to stop blowing up K series gearboxes!
A W series gearbox is a bigger/stronger gearbox... Very strong infact! These are the 'supra' gearboxes that people put behind 3-400hp V8 engines, turbo motors, etc. If you put one of these in your car, you'll be very unlucky to break it. These come factory fitted to the turbo versions of celica/carina/corona, 5 speed GX71 cressidas, and a whole whack of other 80s Toyotas. These will fit pretty well straight into a celica, where as to fit one into a KE70 is a pain in the ass, and so is fitting just a T series box! Which is standard for the celica
I am not going to have the car spotless or anything like it so I am not so interested is having the tacho cable working and stuff but It is important to be easy to have basic drift specs such.
It's pretty easy getting things like the tacho working!
For the corolla there are bolt on adjustable top mounts, top mounts bars and everything. Are there any of these stuff available for the Celica (if you know of course)
Cusco still make brand new camber plates, strut braces, etc for the celica
surprisingly enough! I've got some cusco camber plates.
However the best way to go IMO, is to buy a full set of AE86 coilovers, like the BCs or something. The top plates have a different bolt pattern, but turning them around 180 degrees and redrilling 3 new holes into the top of the strut tower (after some careful measuring) is the way to go.
You just need to replace the existing steering arms with AE85/AE86 ones, then it all bolts in. You can also use aftermarket AE86 castor rods, if you want some that are rose jointed or whatever.
Another option is to buy the S13 silvia coilovers, and have the struts welded to the bottom part of cut down Celica struts.
also for the Corolla you can find short shock absorbers so that you can ride really low but still having working area (did you understand?).
Short stroke AE92 shocks fit into the celica casings, are the best option. Rear shocks from an SW20 for the front, or Front GT4 shocks are also an option, but are shorter/lower than AE92.
Also the guy that sells the Celica says it is 1600cc 87hp so will this gearbox be OK even with the stock 4AGE?
Yep, will be the same gearbox that the 4AGE celica uses anyway.
I've read that the Celica diffs have big diameter rear axles that are unbreakable in low powers since the diff is going to be welded not changed with an LSD.
Again, KE70 comes with a smaller diff (S series?) from factory compared to the celica. Minimum diff size that the celica comes with is T series, which is the same strength as used in the AE86. (You'd have to find an AE86 diff for the KE70, good luck with that)
Do you know the weight of the Celica (i think it is 200kg lighter than corona TA60 - which never came to Greece btw)
Depends on the trim level etc, but approx between 1000-1200kg in standard guise. If stripped out for drifting/racing/whatever, I'd expect it to be around the 1000kg mark, or possibly lighter if using T series diff and gearbox, and a 4AGE.