which engine can you build and get more power out of and perform better?
I am leaning towards using a 5.0L out of a mustang, I am aiming for 700+ without nitrous. I figured a 5.0 would weight less and have more performance parts than my 5.4. I would like to get 700+ and still pass smog even though I know that not very likely.

 

Your asking for more than 2.3 horsepower per cubic inch for from either motor.
That requires a lot of money and running the motor at high RPM to pass enough air to make that kind of power..
For what application is your intent?
Unless it's a drag truck for that specific use, it's not practical.
It would not pass emissions, or even a visual check.
700 hp from a small displacement requires the use of systems such as super chargers, Turbo charging etc.
Good luck.

 

So you want to put a $10,000+ engine (and new transmission) into a 4500 lb truck worth maybe $5000?

 

Neither block will handle that HP level.

 

It will be a drag race truck for 1/4 mile and I had planed on running supercharger.

Yes I am planning on putting a lot of money into a truck worth around 5000, I want to drag race a truck and the body style I have is sporty enough. is that a problem to you? blupupher?

 

So long as you know what your in for, no I don't have a problem.
Many people come on asking about doing what you want, but don't realize the cost of doing it.
You never stated in your first post that you were planning on a racing only truck, which also makes a big difference. You did state you wanted it to pass smog, which sounds like you want a street legal truck?