Are my intake manifolds usable?

So I ended up ordering a set of Murray's carbs, got them installed and couldn't get the thing to idle that well. Note, I've never had this bike running until today...

I've bought Murray's carbs before and didn't have doubts about his products, so I dug into it and undid my throttle cable, idle went from a screaming 8000rpm, to a yelling 4000rpm.
Turned the idle screws each way 1 turn and didn't really make a difference, so I took starting fluid and did a quick spritz around the intake boot, 1 2 and 3 made the idle jump and 4 didn't,took everything back apart and found this.

I only took off 1 and 2 and both look almost identical... The reason I'm asking is I know obviously heat and rubber will ha e issles, so I'm not sure if these cracks on the inside are causing issues?

I looked on xj4ever and the intake boots are over a hundred dollars each... About took my breath away.
If these are toast, is there a good place for some cheaper intake manifolds?

Also, there is no spot for an o ring, that thing is rock hard, and won't come out or move, also the gasket on the engijne looked to be some form of rtv? Maybe I just need new paper gaskets?

 

False alarm... Quickly realized after focusing on the cracking that there was no gasket and these have no oring spot.
Bought a full gasket set when I first got the bike and it had the intake gaskets, so I plopped them on with a bit of great stuff on the intake side, after a few splurts, it fired to life and idled...
After a thousand dollars in parts to get here, an ungodly dirty bike that still needs another thousand to get on the road, and maybe another grand on top of there... But man, hearing it idle was the best feeling in the world.
And I didn't wanna put gas in a tank I'm jot going to actually use for awhile.... So my Suzuki savage tank is acting as an aux tank! Haha

 

They're called "carb holders" in the parts diagrams. Looks like there are repro sets that go new on eBay for $58 ... for the set of four.