Interm Engine Buildup.

[LOAF]

I am trying to do some research as I build my GL Vert.. I am currently working on the suspension followed by the body and interior.. My last phase will be the engine.. Depending on how money is.. I would love a Type IV... but as an intermediate engine I wanted some thoughts on the following..
I live NNJ so I deal with the rollers at the DMV emmission station.. That being said, some have suggested keeping my stock 1600 DP EFI L-Jet engine for this purpose and having a second engine for fun..
As far as maintaining my engine stock.. I really would like to extract some more power out of the L-Jet system.. I was hoping to increase the displacement to about 1.8 or 1.9 lt.. via differrent Piston/stroke combinations.. Haven't put thought as to which.. The problem I hear from people is that the valve sizes are to small.. Can't I invest in a shop to increase the valve size to compensate for the increase in displacement..
Also planned on a less restrictive exhaust..
WHAT or HOW can I tweak or replace the Air Mass Sensor to pickup the pace to compensate again.. Can I use some parts off a Vanawagon or other L-Jet Varient that Has a larger displacent.. will I havet to switch to larger injectors..

Don't want to break the back..but since I was thinking of having this engine rebuilt correctly, I wouldn't mine spending a little to have a nice (80+ hp) engine for fun and inspection..

Thanks and appreciate feedback..
Alex