I have been concidering a V8 swap for my 04 ford ranger XLT. I have been looking at 302 based engines. What is the biggest V8 platform that I can fit in to my truck with out major body modification?

 

As big as you want but it is not always practical.
All around performance, and easiest fit without changing things in the engine bay too much, is the 5.0L.
There have been a ton of these done but on an ’04 not sure !

Review all of the How To’s and the Threads on the subject, then decide if the swap is good for you.

Now as far as a stroked 5.0L, you can go to 347 CI even from Ford.

 

A 302 in a 04 or newer would be tricky. I would try to use an donor engine that is similar in wiring platforms.