motorworxs on m.net bored the hell out of his 1.6 liter and found our blocks have alota beef to em. If you wanna know about the tolerances of what it will take getting with him would be a good idea.

 

You could do the exhintake cam swap for a little bump. It's generally agreed upon that it will net a 8-10whp bump naturally aspirated. I did it myself a couple years back and it was worth the $60 I spent on the drilled cam gear and the exhaust cam. I noticed a power bump higher up in the RPM range, and FWIW my car dynoed at 116whp with a stock crossover tube (cowl intake attached to stock air filter box) and stock exhaust. I didn't get in dynoed beforehand, though.

Basically what you do is chop the CAS flange off the stock exhaust cam, swap it with the intake cam, put in your redrilled cam gear and you're good to go. Here's a guide for it: ExhIntake Cam Swap