I have a couple of 1/2 oz Strike King Red Eye lipless crank baits that need to get their hooks replaced. What is the correct size? Any specific model you would point me towards?

I believe they are #4. I shy away from round bend trebles as these baits become easier for the fish to shake off as you go up in weight. I like these; https://www.basspro.com/shop/en/mustad-triple-grip-treble-hook-2x-short-shank

for two reasons. Their design and the barb is more pronounced than on some others.  You still need to keep a hooked fish from jumping, but if you do your part, you won't loose many.

I've been known to throw a RES now & again.

And I agree with @papajoe222 I also like the Mustad KVD 1x Strong 2x Short Triple Grip Treble Hook.

 I change out every stock treble with them. Just not always in the red however.

And while the bait come stock with #4's, I like to kick it up a notch and go with a #2 on the front and a #4 on the back.

A-Jay

I use #6 for all, because Walmart had the Eagle Claw #6 for 25 pcs for $4.50. Never lose a fish. Too bad, Walmart no longer carry these, now they carry the 3x red ones. 3X is too strong for my 12 lb line to bend it when snagged.

9 hours ago, A-Jay said:

I've been known to throw a RES now & again.

And I agree with @papajoe222 I also like the Mustad KVD 1x Strong 2x Short Triple Grip Treble Hook.

 I change out every stock treble with them. Just not always in the red however.

And while the bait come stock with #4's, I like to kick it up a notch and go with a #2 on the front and a #4 on the back.

A-Jay

Can you explain the reasoning behind putting different sized hooks on?

11 minutes ago, pauldconyers said:

Can you explain the reasoning behind putting different sized hooks on?

The general theory is to use as big of a hook as you can without the hooks being able to foul up on each other. The bigger the hook, the more likely that bigger throat is going to catch onto something in the fishes mouth whenever they hit it. 

18 hours ago, govallis said:

I use #6 for all, because Walmart had the Eagle Claw #6 for 25 pcs for $4.50. Never lose a fish. Too bad, Walmart no longer carry these, now they carry the 3x red ones. 3X is too strong for my 12 lb line to bend it when snagged.

Thus is the Walmart way: replace things that people like with things that they don't like.