You don't necessarily need an 89 crossmember. You do if you wanna make the engine mounts fit right in place, like if it were stock...
But you could have someone weld that mount (only 1 mount is different, the other one fits right, and it only has 2 mounts plus the tranny one, which also fits right), and it'll be much cheaper than finding that crossmember. (though I don't know how much they cost, but probably a few hundred bucks). So welding it there might be cheaper.
The shop I'm gonna do the 1JZ swap in has done this to a lot of cars. All the SR20's I've seen in cars like old Datsuns and old Corolla's (the 1.8 RWD ones from the 80's), and also yesterday I saw a 1JZ in a Hilux pickup... and they have a Trueno and a little Corolla 74 with a 2JZ and a 3S respectively, and they tell me all of those cars have some mounts welded, and it never breaks. The trueno and the old corolla are both int he 9-10 secs 1/4 mile. The trueno is even using the 7m-gte tranny. So I think crossmember will not be a problem for me...
Just take it to a shop that knows what they're doing and have experience. =P
My advice might not be the best, though.
