Its certainly not the noblest thing to do, but possibly the smartest. Seriously, you'd think that by that stage most guys in Basciano's position have shred any notion of "nobility" or "respect" in that life, where they are false anyway, false ideals. And considering all his "friends" are people he'd murder/be murdered by if the order came down, I think it would be incredibly naive to still harbour protective feelings towards any of them at that point, especially since so many of those "friends" are who put him where he is. The only "friends" he'd rat on can only be ratted on because they're criminals, & if he's smart by now the only people he should really be caring about is his family & the people who would prefer he talk & live rather then stay silent or die. It wouldnt be his true friends he'd be ratting on, whether he knows it or not.
I know we disagree on some stuff, but its at least my own opinion that unless he realises that there really is no place for the way he lived his life in todays society & does what he can to curtail the efforts of his criminal brethren, its a lost cause anyway.