SHELBY GT 350 Member
Joined: Sep 2010
Location: see user name
You can open things up all you like but ultimately displacement is a severely limiting factor. Forcing air into it overcomes displacement and less than awesome cylinder head flow and combustion chamber design. Internal combustion engines are nothing more than air pumps.... These ones just happen to be limited on how much air they can draw in on their own.
2001 GT Convertible
All the usual bolt-on's /200 I6, C4
And a few Explorers too... 2008 4.0 XLT 4x2, 1996 XLT 5.0 4x2, 2003 Sport Trac XLT 4.0 4x4