Help!
 

I absolutely love mustangs and have always wanted one. I have a limited income right now and need a car. I was thinking of buying a V4, but i want a 5.0, can i switch this car to the one i want? and if so how expensive would it be?

first off there is no such thing as a V4. It is an in-line 4 or stright 4. What type of V8 do you want. MM&FF put a 351W in a 4 banger for about 3000 dollars. IT was used parts and they did it there selves. You can spend unlimeted amouts on it. It just depends on what you want.

buy a 4 banger it'l cost you about $300 then build your v8 the way you want it buying it a part at a time you can get the v8 at a junk yard for about $150 and rebuild it. and you can drive it around while you build the v8 it should only take a day to put the v8 in and you can drive it to work the next day.

Buy a 2.3 Mustang and yes, you certainly can installa V-8 in it at some later date.
Understand that although the 4 cylinder and the V-8 are basically the same car, there are a lot of subtle differences, besides the engine, alone.
The V-8 has different suspension (spring rates, rear anti-sway bar), wheels and tires (the V-8's are much larger/wider), exhaust (V-8 has true duel exhaust with two catalytic converters on each bank), motor mounts have to be changed and of course, the electronics are different, too.
Switching a 4 cylinder Mustang to a 5.0 is not rocket science, but it's not like doing a tune-up either and there is some expense involved to do it correctly.

Plan ahead, go slowly and get a Mustang that has a very clean, rust-free body in a style you really like and enjoy it while working on the 5.0 engine you'll eventually install.