Haven’t received parts yet, but bought a complete lot of high-end aftermarket small block heads, blocks, intakes, and stock blocks, etc. It was a good deal so I didn’t hesitate to pass it up, but probably should’ve asked more questions.

Do some of the small block parts interchange with each other? Intakes could be modified or use spacer plates to work from block to block type? How many types of intakes or heads are available? I deal with mostly big block or HEMI stuff.

Define “high end”....

I did....”high-end...aftermarket”

come on man the good ones

As in high end China race stuff or real American race parts?
Did you get a R block with American brand after market race heads?
Or is it a stock block blue printed and ready to assemble with the pistons, crank, bearings, cam and so on?
I would ask around $6000.00 more for a R3 block with a really good set of ported high end heads and all good race parts in it compare to a stock block with stock big valve heads set up as a decent 600 HP bracket race motor

How many of any part is hard to say since the small block was first produced back in 64. If you are not familiar with this stuff how did you determine it's a deal you couldn't pass up? May be post some pics and further info on what you have then ask questions.

If its an aftermarket block is it a Ritter block? I would consider a R3 block factory same with any of the W series heads as they were produced by or for Mopar. Indy heads ? perhaps Brodix B1BA ? Edelbrock?

Why not list what you have? Not everyone's idea of "high end" is the same.

Yup, that right there is the key point, what are you KPIs?

For an amateur like myself, something like a combo of R block and W5 heads would fit the label of "high end"...but again, I'm just a DIY guy hanging out in my garage who likes to try out stuff, far and away from a pro shop builder who may be dealing with customers spending thousands of dollars each season building a better motor, right?

Ahhhh! R5/P7! ...not just some ole truck junk!

Well , R-3 blocks were available with 340 , 360 or small block Ford mains.
In at least three deck heights as shipped and several options from there.
Let's not forget 59 or 48 degree pushrod angles and siamese or standard cylinder arrangement.
Wet or dry sump ?
Not much interchange between W-7 , 8 and 9 stuff...........and I know there were at least two different types of shaft rocker arrangements for the W-9.............probably more for the W-8 depending on who built them.
I learned all that when building one R-3 , W-9 motor.
Get ready for an adventure if you are planning on screwing together motors out of your parts bonanza.
If you're just going to flip the stuff , there is a market , but it helps to know what you have.

Well with the information you provided...

Yes.
Yes, some could be.
A lot.
I see either a fire sale or much education in your future.