Try driving both side by side

. I know GM's figures for the 3.2 were optimistic. No idea where those dyno figures posted came from, as certainly does not tie in with *ANY* 3.0 or 3.2 I'd ever driven. I'd I've driven an awful lot of them. And 2.5/2.6. And the poxy little 2.0/2.2, and soot chucker variants.
The 3.0's limitation was the exhaust fanimolds, easily resolved by using some from the 3.2. The 3.2's limitations where the incredibly low compression ratio that needs stripping and rebuilding to overcome... ...although as said previously, that low compression might come in handy if you want to bolt some kind of forced induction on.
Therefore, comments still stand, if you just want to drop in an engine, the 3.0 is the best of the V6. The 3.2 has the potential to be better if you want to through several grand at it (but then I'd argue there are better engines that could be used as a base if spending that much).
And as an added bonus with the 3.0l, you get decent economy off it. 400 miles from a tank doesn't take much effort, even I've managed over 500 miles from a tank. Even trying very hard, I never managed to get less than 330 miles. With the 3.2, 350 miles from a tank was about the best I ever achieved.
For info, the reason the 3.2 (and 2.6) were enlarged over their original engines was due to cost cutting, which lead to having to reduce the CR, so they had to increase capacity be a noticeable amount to get power back in the same region. This allowed them to remove the EGR and SAI, and using a (awful&) electronic throttle allowed the removing of the IVC. For good measure, they also fitted crap, restrictive cats, which anyone with a 3.2 should consider swapping out for 3.0l ones as near bolt on replacements and remaining road legal.
*The electronic throttle was mapped to provide lots of throttle with minimal pedal movement, giving an impression of it being more powerful than it is, where as in reality, further throttle movement shows it to be as flat as a witches tit.