700HP really doesn't tell us anything about the weight of the engine??
Aluminum block and head engines are much lighter than cast iron.
What is the base model of the V8 engine?
302-450lbs, hey it's possible, lol, Saleen 302 just out at 730HP
Will it have single or dual turbos or superchargers?
And I assume a '94 Ranger, but what model, and 2wd or 4wd, and what was the original engine?
4.0l ran about 430lbs
Lima 4cly was close to 430lbs, lol.
Good read on Ranger suspension by year/model here: The Ford Ranger Front Suspension
Obviously the frame and other parts also have a weight limit, not just the springs.