That's where its cheaper for the 1J, bottom end is bullet proof unlike the Rb25 over @ 300RwKw, 1J injectors good for @250 RwKw - Rb25 runout by 200Rwkw, the manual toyota box is a bit how ya going shift wise (R154) but plenty around behind 2J cars so definately strong enough. Dump pipes for the factory twins are a challenge, but I made 2 x 2.5" ones for my Cressida and got them to fit around the steering, so it is all doable. 1J for the win, they are a great motor.