Well certainly but early 1990 cars weighed a hell of alot less than the newer versions, the 16v Golf GTi, 16v Astra GTE, 205 1.9 GTi, RSTurbo, 405 Mi16 and a few others good be tuned quite readily to around 160-175bhp before throttle bodies/45's and had compare-able 0-100 times. And besides the whole idea of a hot hatch was still a developing one, there were plenty of 200+ bhp donar engines that pretty much slotted in. Such as a c20let into a mk2 astra/nova.
Didn't you watch the episode of Top Gear, when they compared old and new? Old won ;) 45's and 48's are often upgrades off standard lower grade injection systems but carbs still fueled 700-800 big block hemi's, of course you wouldnt see a carb on a 1000 bhp skyline or supra ;)
Not in my experiance, it depends on what swap you are doing, for instance a redtop/ecotech nova is a much more simple affair than a 205 with an mi16.