I'm on a learning journey and want to understand if these two discontinued 22 RTE specific parts are different or could they be identical with a different part number because of something Toyota does with part numbers in the 25xxx-xxxxx category?
I have two EGR Valves, both are specific to the 22-RTE and are the same size and shape. They are not supersessions. Also, this is not about keeping vs deleting the EGR system.

• Part #25620-35150 is for 08.1985 - 08.1986 Pickup
• Part #25620-35171 is for 11.1985 - 08.1987 4Runner

I checked the following and no differences:

• Vacuum: Both begin to open at -100 mmHg and are fully open at -140 mmHg
• Vacuum Modulator: same part # for both
• VCV: same part # for both
• BVSV: same part # for both

Although the EGR Valves have different part numbers, everything about them seems identical including the vacuum specs.
Could these be identical parts, but assigned different part numbers for some reason? What other test/check can I do to find a difference between the two?

Pics of the two EGR valves. Both have a restrictor button/plate in the lower port, but that came off the EGR Valve in the first photo and I didn't put it back on when I took the photo.

 

They very well could function the same. CARB was pretty restrictive on turbo vehicles, the different part numbers may have been done to satisfy one of their requirements.

 

The one difference I was able to find was the size of the restrictor plate. The opening for the Pickup is 7mm and the opening for the 4Runner is 8mm.