Iron to aluminum engine block swap??
 

I have a 2004 4.6L F-150 engine that I bought to put into my Austin Healey Kit Car. I was wondering the following.

• I need a low profile intake manifold so that I can close my hood. Are there any from mustang or another car that will fit it?
• If I want to swap the iron engine block for an aluminum and use all the rest of my parts out of my original engine, what type block do I have and what type aluminum block can I use? Also, what ford models and years are swappable candidates for me?