GMC oil pumps will physically fit, they have 60 PSI relief settings, and are quite a lot larger than the chevy pumps. You would probably need to fabricate your own oil lines and pickup. I am not certain of the volume, but it appears to be big enough that you might actually get or approach the relief setting. All the old hot rod manuals say to use them for more oiling. But unless you are turning it 5000 RPM it really won't be necessary.
