sorry to revive an old thread. I'm new here. I've been working on a 2jz 84 regal off and on for a couple months. I picked up the regal with a plan to do that. I had an 87 supra that I had swapped a 2jz into from a Japanese Toyota aristo. so I'm familiar with the engine layout. it was stock 280hp that was easy to push to 426 to the wheels by pushing the boost up and building a map clamp to hide the boost from the ecm. Japanese engines don't usually make more torque than v8 engines but they make up for that with gears. the stock gears in my supra were 3.91, which to an American car would be a good upgrade to. I had a 4cyl 4runner that has 4.56 gears from the factory. it was slow on the highway but it could pull a broke down f250 that was pulling a boat. so... to overcome the lack of torque just adjust the gear ratio in the rear end and you will be fine.