I am currently restoring a Hyperball and am a bit confused about the ROM types and sizes on the accompanying Williams system 7 MPU board.

I would like to update to ROM L6 for U20 (game ROM 0) with accompanying ROM L4 for U14 (game ROM 1) and U17 (game ROM 2).

I have modified the board to use 2732 EPROMs for Leons test ROM at U17, so that part is ok.

The schematics states that U14 and U20 should be 2316 type ROMs with 16384 bits/2kbytes capacity.
The L4 ROMs found on IPDB however are 32768 bits/4kbytes in size however.
Does this mean the board can be jumpered/changed to accept 2732 EPROMs in all positions ?

Also, Pinwiki states that Hyperball uses standard blue flipper roms : https://pinwiki.com/wiki/index.php?title=Williams_System_3_-_7#Flipper_ROMs
Planetary pinball however indicates they use a separate type : http://www.planetarypinball.com/mm5/Williams/tech/checksum7.html

Ok, thanks, I'll consider my options

Yep, or making an adaptor board I guess.

Maybe this would work ?

https://store.go4retro.com/23xx-adapter/

Going to give this one a try : https://github.com/TheLittleEngineers/2732-to-2532

Doing the same modifications on the board for U14 and U20 as is done for placing a 2732 in U17 seems to do the trick.
At least the board is booting now