[RallyBob]

I'm planning on doing an engine swap and hopefully getting the thing up to 300 HP. Will the factory axle handle that kind of power??

I've exploded MANY rear Opel axles with under 150 hp. With 300 hp, and more importantly, higher levels of torque, you will likely destroy the rear axle on the first day you get your transplant rolling.

Going by the vehicle width, I've always thought a Miata rear suspension would work well on an Opel, but with 300 hp, you'd have to swap in the RX-7 differential. This was done a lot with Ford 302 transplants in Miatas a few years ago.

Bob