4.30's: Noisy Gears?

I have been a member of StangNet for a while, but I usually just use the search to find my answers. I cannot find any answers for this though:

I have a 97 Cobra with 12k miles on the ticker. I just bought some 4.30's and a SpeedCal. The shop that quoted me for the install said "The 4.30's do tend to be known for some noise which I assume you would know about." I didn't. I have heard a lot of great things about SpeedInc in Schaumburg, IL...but:
Will 4.30's definitely have noise?
What does the noise sound like?
Would I be better off with 4.10's? (i'm staying N/A)
Should I find a different shop? (suggestions in Chicago)

And since I am posting, what do you think about my other mods? (suspension is coming this year)

Any advice is greatly appreciated.

Thanks!

~Jeff

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1997 Mustang Cobra
Magnaflow Cat-Back Exhaust
BBK Ceramic Coated Long Tube Headers
BBK Catted X-Pipe
BBK Cold Air Intake
Accufab Throttle Body
Steeda Underdrive Pulleys
MAC Timing Adjuster
MGW Shifter
17x9 Chrome 95' Cobra R Wheels
Front: 245/45/ZR17 Nitto 555 Tires
Rear: 275/40/ZR17 Nitto 555 Tires

FLSVTCobra said:

I have a 96 Cobra with 4.30 gears from Ford Racing. They make no noise. 4.30 gears is the way to go with these motors, they are not as bad as everyone thinks, even for daily driving.

Click to expand...

Thats what i've read everywhere, and have heard a lot of people who got 4.10's and regret not going for the 4.30's. I can't wait to see what they feel like...

And, yeah...I can't see why the gears would be more likely to make noise than 4.10's so I need to decide if I need to find a different shop...hmm...