If you know where to look it really isn't that expensive. There is aftermarket support (mostly in Australia and New Zealand though). After a little research there are 86s with 1UZs in rally, road racing and now drifting. The weight isn't that much more but what doesn't help is the tranny(5spd R154). So if you do have to add weight at least it comes from pretty much the middle of the car. The key thing for the swap is getting that bellhousing adapter to make it a 5spd. You also get to stay all Toyota and n/a too

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The thing that will add money is the new set of rims and tires you need for the power and torque lol.