168 Pin EDO exists ! But actually I think this computer uses BEDO (Burst-EDO).
Thank you for the image, I have added it here http://www.win3x.org/uh19/motherboard/show/2996

DIMM or SIMM just denotes the type of physical socket and has nothing to do with the actual memory technology. There is a notch on DIMM sticks to indicate 3 or 5V.

The Intel PR440FX, the quintessential i440FX dual PPro also uses DIMM slots for EDO-ram. Same for the Compaq workstation systems. EDO on DIMM can be 3 or 5V, so watch out with EDO-SIMMs.

BEDO was nothing more than a paper launch, although the 440FX might support it, you will not find BEDO-ram in the wild.

so the exact wording to put in the ebay field would be? I don't want to take any chances of buying the wrong ram.
Thank you

Try searching for: "EDO DIMM 60ns 3.3V"
According to the manual, this is the type of RAM module you need. You could also omit the "60ns 3.3V" part in the search form and go for "EDO DIMM" only which will give you more results, but you'll have to pay attention that the modules meet the 60ns and 3.3V specification. Do not go beyond 128MB per module because that seems to be the maximum supported (there are 256MB modules out there).

System Memory […]
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System Memory

Four dual inline memory module (DIMM) connectors are provided on the system board. The DIMM connectors are powered by +3.3 volts. Each DIMM connector is a 168-pin, gold-lead socket. For the pin assignments, see “System Memory Connectors” on page 30.

The system board supports:
* A maximum of 512 MB (128 MB modules in all four connectors).
* Dynamic random access memory (DRAM) only.
* 64-bit (EDO) and 72-bit (ECC) wide memory modules.

Any configuration of DIMMs is acceptable. Characteristics required by DIMMs include:
* 168-pin, unbuffered +3 V modules only.
* Gold-lead tabs only.
* 60 nanosecond access speeds only.
* Height of no more than 3.81 cm (1.5 in.).
* To enable error-correcting code, all installed memory must be of the ECC type (a combination of ECC and nonparity types is configured as nonparity)

Note: Single inline memory modules (SIMMs) are not supported in the PC 365.

The manual of the PR440FX never mentioned 256 MB sticks, as they were not available at the time.

But the chipset can take 1GB of ram, my system is happy with 4x256 T-shaped EDO dimms.

gex85 wrote on 2020-09-01, 14:55:

Try searching for: "EDO DIMM 60ns 3.3V"
According to the manual, this is the type of RAM module you need. You could also omit the "60ns 3.3V" part in the search form and go for "EDO DIMM" only which will give you more results, but you'll have to pay attention that the modules meet the 60ns and 3.3V specification. Do not go beyond 128MB per module because that seems to be the maximum supported (there are 256MB modules out there).

System Memory […]
Show full quote

System Memory

Four dual inline memory module (DIMM) connectors are provided on the system board. The DIMM connectors are powered by +3.3 volts. Each DIMM connector is a 168-pin, gold-lead socket. For the pin assignments, see “System Memory Connectors” on page 30.

The system board supports:
* A maximum of 512 MB (128 MB modules in all four connectors).
* Dynamic random access memory (DRAM) only.
* 64-bit (EDO) and 72-bit (ECC) wide memory modules.

Any configuration of DIMMs is acceptable. Characteristics required by DIMMs include:
* 168-pin, unbuffered +3 V modules only.
* Gold-lead tabs only.
* 60 nanosecond access speeds only.
* Height of no more than 3.81 cm (1.5 in.).
* To enable error-correcting code, all installed memory must be of the ECC type (a combination of ECC and nonparity types is configured as nonparity)

Note: Single inline memory modules (SIMMs) are not supported in the PC 365.

Note the "unbuffered" bit, that's as important as 3V 168p. Also "DIMM" could also give non-PC non-168p form factors.

So "unbuffered 168p 3V EDO".