We recently had a customer reach out with a common AFIS Injector installation challenge..
Customer Question:
“Hi, I got a set of AFIS 400lb injectors and I went to install them into my Small Block Ford with a Holley Hi-Ram. I can't seem to get the rail to sit down low enough to be able to mount it to the manifold. Have you guys come across this issue before, and is there a solution?”
Our Answer:
Yes — this is a known clearance issue with certain intake manifolds (Including the Hi-Ram) built with a stepped injector bore, designed for O.E. style, single o-ring injectors. However, AFIS injectors utilize two full size, lower o-rings. The solution? Simply remove the bottom o-ring from the injector. This will not affect the performance of the injector.
Customer's Response:
“Perfect! Worked like a charm! I had measured it and it was about 7mm too tall — with the O-ring removed it dropped almost exactly 7mm.”
Takeaway:
If you’re running AFIS Fuel injectors on an intake with stepped injector bores, and your fuel rail isn’t seating properly — simply removing the bottom o-ring is the quick and easy fix.