??????????? Unless they are restricted to a tiny 2L engine. If thats the case then why enter the 350?
But you really should really have a good balance with weight and power. If they wanted a lighter engine then theres plenty other better and lighter engines.
All you need to know here http://www.modified.com/sportculture/feature_nov01.html its a SR20 350z Slider They blew up the VQ and wanted something cheap and nasty that they can pilfer parts in any back yard in Aus, so they went 2L 4 cyc, every man and his muppet has one and does em up like its a ferrari =)- lol They've got 402 hp at the wheels and its not going to pop a piston or crack a rod. The heads been hi-flowed insanely and bottom ends all nissan. Have a read its almost interesting, definately unusual.