3s harder to fit. 1G can be tweaked, and it can put out enough power to propel your car like a bat out of hell. The only problem is that it is a heavy engine. Not sure you would want to put it into a lightweight Celica. Your car is beautiful btw.
basically, i'm trying to keep up front costs down but not fuck myself over in the long run. my 22/20r went 13.9 all motor. i was planning on going 12's but i cuy the project short shy of pistons, bigger carbs and ignition. 12.9 wont be enough. so i figuer i'd go 22r turbo... nah thats getting to costly in the planning, so then i said hey i'll go 7m... and that got costly too. so now i'm looking at 1jz front clips for 2000... seems like a steal to me, 290 hp at 10 psi... i figure abotu 50 hp from downpipe, 3" mandrel piping and a straight through 3" muffler, and another 40 or so from running 15 lbs and a filter. so now i'm looking at a very very near stock 1jz with low (for toyota 60k) milage .. so ive got daily driver reliability. which is good seing as this is my daily driver. and a 11 second car.
i think 390 hp should be enough for 11's in a 2300 lb car (thats with full interior) on slicks.
i havent decided on final drive gearing, right now ive got 3.73's i'm thinking about going 3.08 but i never push it hard on the interstate anyway... i'd like to not limit myself top end wise (you know for those runs against hiyabusas) lol kidding there, there celica just doesnt have the drag efficiency to do much abover 140. anyway i apreciate the comments on the car. its a rusty junker but its hard restoring your daily driver