Right. With these gm style ones tho. The dcmh ones are the only ones i know that require an external check valve. Wondering why that is
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You really should use an external valve with the new OEM style pumps and Kjet.
I removed the check valve after converting to EFI and you can hear the accumulator spring expand as the fuel drains back after key off.
Here is the check valve:
https://www.usplastic.com/catalog/it...5394&catid=956
It's the one I use and I believe it is the same one DMC uses.