What is the normal thickness of a sleeve? Let’s say for the 440 standard bore. Can one order any outside diameter?

Call Darton and see
I like and try to make sure all the blocks I have sleeves install in are Darton brand Ductile Iron sleeves not your standard over the counter cheap rebuilder sleeves
Make sure your machine shop knows how to properly install them also

1/16" wall

Wow, that is thin

I thing you dropped a decimal number poly.
I don't believe i have ever checked a factory block that was only 0.0625 thick. 3/16 I would buy or even 1/8

3/32 is the most common size.

Smaller than 1/16" invites distortion when installing.
Thicker than 1/16" invites transecting the water jacket. Only use a bigger size if you know it's been done before.

Look up the available sleeves 3/32 is the standard. they also come in 1/8 comonly.
1/16 is rare/special. Not many offer in that size.

Mike, on my 383, I had to have 2 sleeves installed. They were dartons and were spec'd for a chevy. .145" wall thickness, after boring/honing they were .095" wall.

the melling sleeve for a 440 is p/n CSL121. it is 3/32 and an outside Dia. of 4.510

There is a 1/8 version but no 1/16.

Also, melling makes thousands of standard sleeves, so yes you can pick a different one for a different application, if desired.

This^^^^. Get the thickest sleeve you can with the closest nominal bore size you can find.

On typical small and big block V8 engines, I never installed anything thinner than an 1/8" sleeve.

Well good answers but I didn’t want the cat out of the bag at first. My bore is 4.53, pistons are $1900 new, I have a set of 4.31 on shelf so I figured sleeve it down to that size, not even boring the block just get the nominal outside size, drive em in with green loctite then bore-hone to fit pistons.

If you want to distort the bores drive them in, if not wanting to drive them in chill them in the freezer several days or pack them in dry ice and then drop them in.
Make sure the O.D. of the new sleeves is less than .0030 of the bore sizes, check all 8 bi=ores before ordering the sleeves. Most of the better auto machine shops I've used out here leave a small step at the bottom of the bores when prepping the blocks for sleeves

I wouldn't rely on sleeves fitting an existing bore to many variances. They need to have a step to sit on also, unless you use a top flanged sleeve which still requires machining.

Also on the freezing. I don't do it. I tried it once and with the frost that accumulates on the sleeve I didn't want water in there with the loctite. .001 to .0015 and send it home.

I've used the 3/32 sleeves many times and always chill them in the freezer, they're not always round so you have to take an average.

Yes to leaving a step at the bottom of the bore so the sleeve can't drop.
I'd throw the block in the hot tank for about 20 minutes and put the sleeve in the freezer for several hours. Take the block out and as soon as it was dry, drive the sleeve in w/ green loctite/sleevetite. I was concerned about the moisture from it being cold w/ the loctite, but never had an issue. Repaired one really bad 454 chevy block out of a tow truck once that had a huge piece of cylinder wall missing. Concerned enough that I told the owner I'd try it, but if it failed it was his, lol. It ran for several years that I know of after I fixed it.