You dint list the cam duration nums for the last cam, so it's a little hard to compare with the OE stuff. I notice the info on the OE cam you found was from Joe Lucia over at NCRS. He is THE GM Parts guy, so his info can be taken as gospel...and usually is. However....the duration #s for the OE cam you listed(GM# 14044613) seem a bit high, imo. That's a pretty healthy spec for an L83 Crossfire engine. Normally, duration #s around 310-320 tend to create a pretty good "lope" at idle, and don't help create much idle vacuum.
Now then...if this is not a stock L83, and it apparently is not, then things change. IF....IF the cam you have in your engine now IS the one with those higher duration #s, then that can very well be why you're having trouble with the Smog cops.

What kind/brand of "crate" engine do you have, anyway? Is it supposed to be a stock replacement for the Crossfire, or is it something else?

It was purchased by VIN number so it was suppose to be for a Corvette but after lots of people trying to make it work correctly one shop discovered it was not the correct camshaft. Do not ask me how they discovered that I have no idea. 

 

They also said they could get it to work they thought.  They did get it to smog.  Not trusting them I took it to a friend's shop and he came up with close to the same smog numbers they did.  So I know it was a good smog. 

 

But it still did ran poorly at idle.  I contacted the people that the engine was purchased from and they would not give me a build sheet for the engine.  They finally told me that they build the engine to fit in the "Standard" Chevy and it was not a Corvette specific engine.  I asked why they wanted the VIN and they failed to provide a good answer except that the vacuum was a little low and that was my issue if I took care of that everything would be great.  They also told me not to call back they were done discussing the issue.  

 

That leaves court but they have the engineers that will tell the judge that the engine would work and of course they will state they have been doing this for a long time and I'm the first complaint.   I know the routine I have been on both sided of court actions.  It is who has the best expert and the cost is not great enough none of the local corvette shops are interested. And besides I cannot really prove until I pull the cam if it is the correct one or not.  I'm also not sure changing the camshaft will answer my issues.

I know that the heads are most likely a little different not sure what issues this will cause.

I may not have any choice but to go to court.  I do have until May before the year is up and I can no longer go to court.

Otaaaay......that's a little more info! Most engine rebuild/reman places don't build engines for "specific"applications like that. They usually just build them pretty much all the same. They will tell you it will fit and work, but that doesn't mean it will work as well as the "correct" engine would. Since you have the Crossfire set-up(I assume you still do?), that kinda opens a new can-o-werms. Vacuum leaks are fairly common on those things, with the intake being the most likely to cause a problem.
The only way to know for sure what cam it has, or the specs on it, is to use a degree wheel, a dial indicator, and a piston stop(to find TDC). It's a big pita to do, even with an engine on a stand outside of the car. I would bet the people that did the engine buy cams in bulk, and use the same one on prolly all small block builds that use a flat tappet cam, with few exceptions. There is a major reman facility here in Dallas that I have been to many times, and I've seen how they work. It's possible(and very likely in most cases) that you could get a reman engine that has heads with the same casting numbers, but with two different valve sizes. I've gotten them like that before, so I know it's possible. It's also possible that the valve guides are shot...or at least one or two. The engine I bought for my 'Burban is a perfect example of that. With less than 600 miles on it, it started having a miss. By the time I finally got around to actually checking it out, it had a completely dead cylinder. The problem was a valve guide that was so messed up that you could actually move the valve around in the head(still assembled in the head) with your fingers. There was so much exhaust blowing past the guide that it literally melted the valve springs for that valve. It's a dang miracle the friggin valve keepers dint fall off, and drop the valve into the cylinder. By that time, my warranty had already expired, so I was stuck with having to fix it on my own dime.
 My point being, "new" don't mean diddly. Hope you can come to a conclusion on WHAT the actual problem is....that will be the only way to hold your own in court, if it comes to that. You'll have to be able to PROVE it was a faulty part/assembly on their part.

I would think that someone like Comp Cams would have a nice CARB legal cam that would go in that engine and maybe even get a little more power out of it.

From when I talked to the guy I'm sure it was just a stock engine that runs on the vast majority of Chevy small block.  That would include the heads.  My understanding is the Heads were also a little different.

So my question is replacing the cam with stock head is that going to help?

As far as the vacuum leak goes the shop has offered to smoke test my vacuum system for me. (by the way this would be a freebee.  I will take it down to them this coming week and get that done.  I will know where and if I have a vacuum leak in the system.  They did not have a smoke test system when I had my engine worked on it is something he purchased for checking BMW which have lots of vacuum leak cased problems also.

Again not being much of an engine guy would replacing the cam with the correct cam even with stock heads help or not?  A little help would be ok I just would not want to make it worse.

Stock spec cam, or even one a little more aggressive, with stock heads should work fin. A lot of folks will use an RV type cam, to get a little more low end torque, without effecting emissions.

So the first thing I will do is get the vacuum smoke test done next week if no vacuum leaks are found work on getting a Cam shaft replaced if there are leaks get them fixed and see how it runs see if it passes smog. 
 




|UPDATED|4/1/2016 8:04:59 AM (AZT)|/UPDATED|

A RV cam like Joel mentioned would be better for low end power. 

Yup...biggest issue there is on the Crossfire....half the dang intake port is covered up on the heads. The Crossfire was an interim set-up to begin with....it was never intended to be used more than the couple of years it was. Once the TPI was released, the Crossfire was a dead issue for GM. The aftermarket is the only place that supports it at all, and the market is getting smaller every day.
So...considering the limited RPM range of the intake, I think an RV style cam would be a good choice...unless you do something about the intake to get more air into the engine.