I was told that this would be a great 10 pin ball for me due to it's core. I used to have a Black Knight (before it cracked and it is a 16lb -now use 15) and I  didn't have as many issues, misses as I do now. I am using a poly polar ice and miss both ways. So I was informed that this ball having a weight block will help. what do you think?

A ball with a weight block will not help (or hurt) you for spares. 

Not necessarily true. Even a plastic with a dynamic core can move when it hits a lot of friction. That's an issue if you're playing spares 100% straight. That's why I don't use my Hammer Taboo Spare for spares. I don't want any unexpected movement, even if it's only a few boards.
 
It sounds like the Op was used to a little bit of hook when throwing at spares, and the absence of movement with other balls is throwing him off. I think it's better to learn to line up with straight lines. You're able to be more consistent over a wider range of conditions.

More than not, most of the issue is bowler error. I am not blaming this on the ball, BUT -- my consistency of making the 10 pin started when I changed to the poly ball. I can throw hard and straight - so i am thinking that the ball with a core, may be BETTER of an option so I don't skate by it. I understand if I pull it, it will probably miss left, unless there is some oil. But knowing I have some room will help, I believe.

I don't mess with spare balls with cores. I too can roll faster and end over end, and when the backends are toasty, I've seen my black ice scoot left if i made an error on my release.

I'd work on my spare game if it was me. Many times it's just a mental thing too.

I'd work on my spare game if it was me. Many times it's just a mental thing too.

+1

I feel you will be searching all ends of the earth to try and duplicate your Black Knight.  Chances are you will not get the same reaction no matter what you get.  Either the ball will be straighter than you like or it will hook more than you like.  In the end you will have to get used to whatever you settle on so it might as well be what you have now.

Some of your inconsistencies could be the difference in weight.  Not sure how long you have been throwing your Ice, but dropping in weight combined with approach and release changes in your ten pin shot could be throwing you off.  Spend some dedicated time working on spares and you will become more confident and will make more spares.

The core won't stop the track spare ball from going in the gutter vs your current spare ball

My Hammer Taboo Spare with the Gas Mask core, going cross lane for the 10, will sometimes hook when my Hammer Carbon Fiber with a pancake core doesn't. Surface dominates, but a strong core sometimes does generate extra movement. That movement can keep the ball from going in the gutter, or missing the pin to the left completely.
 
The choices are to build a spare game where you expect some hook, or one where you go directly at the pin(s) without any movement. Pick one style and get good at it.

ditto with above statements, its not the ball

go to lanes to practice, throw at all spares
in time, you will be able to throw at all spares with plastic ball (except double wood)

to get better, you have to practice, no way around it