Cheaper to fix yours and sell it and buy a V8 as was already said. If you get a donor car with everything then since the bodies are the same you can swap engine, trans ecm etc... over but... again... if you have to pass an inspection you won't pass with a 4.6L car with a 5.0 pushrod in it. Also the 5.0 pushrod is a downgrade.
I'd find a 96-98 GT for next to nothing and swap everything over and PI swap the engine while its out. If you are set on the swap. But not a 94/95.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.