Just pulled the IP off my spare motor, in preparation for installing it on my in-use motor. I can attest that it is possible to remove the IP without removing the oil filter stand.

Easiest way I found to remove the 4th bolt on the back of the IP was a pivoting ratcheting wrench. If you don't have a set of these, get a set and you'll wonder how you got anything done without them. Hard for me to justify spending $100 on a set, but the $20 Harbor Freight version has turned out to be pretty good.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap