If it were me, and ive understood the thread requirements correctly, you plan to frugally tune a 1.7 16v either for use in a 33 as originally intended, or install into the lighter sud, which is a good performance mod straight away being lighter, if you like the sud drive over the 33.
but back to the engine itself, and the all important budget, best bang for bucks, if you're running on adequate sized and well set up carbs, the next things i would do, would be to clean up the heads with some mild port work, and a simple re-face of the gasket surfaces, new studs etc for a perfect fit.
go for cams next, but beware, the more radical, the higher up the rev range you'll need to be to feel any gain, so for a street car this is always a questionable point.
match that to a free flow exhaust, and lighten wherever you feel you can without compromising the comforts you still want.
might sound backward, but consider none engine stuff too.
the right gearbox ratios can transform an engines performance to suit its use, and handling and brakes should also be considered,
amazing how much faster you can go as an average if you can safely carry more corner speed, or hit the anchors much further down the straight!
or, alternatively, do as i should do
leave the beer alone and get back in the gym, lose many an excess pound off the driver, its worth seconds!!!
ps - on a more serious note, be very careful when considering larger CC methods. The quick, or cheaper way, will almost certainly have your project going backwards.
bore increase, skimming heads for extra compression, piston kits etc, should also include extra work and budget to rework the combustion area for squish and flame pattern, and this is where the project gets both clever and more expensive, but without this work, you can end up with the exact opposite of what you intended, i.e. lower compression and terrible cylinder efficiency, equals = less power.......