I need to replace the radio and clock in the center cluster and since I'll have it open, I'm gong to replace the bulbs as well (cause I know @&$# well that once I get everything back together NONE of the bulbs will work - including the backup lights). I know, I know, but that's just how my luck goes.. Question: How many bulbs do I need to order and are they all the same type e.g., 194 or 212-2, etc. Probably gonna put LEDs in replacement. Thank you in advance

Sometimes a website like SuperBright LEDs will list replacements and their equivalent part number for different vehicles.

The LEDs are a definite, brighter improvement.  Order the "warm" version.  The normal lights are a cool bluish light which I tired of after awhile and changed them to a warm version, closer to OE, while I had to have "Doctor Don" (top flight vintage radio repair service in Texas) repair the radio.  And, remember that the instrument cluster will be brighter and nicer than your speedo/tach gauges.  Also, you really don't need to replace the warning lights with the more expensive LEDs unless you want to - but, definitely replace them.  If you search eBay with a "10x" next to your "warm LED lights - C3 corvette" search, you'll find the best deal on a 10-pack.  You can use the remaining lights in your side marker lights.  They are not expensive lights these days.  While installing, make sure to bend out the contact wires on the bulbs to maximize the positive contact with the printed circuit board.  Ask me how I know. 

Thank You, Dave