This may be a dumb question, but do I need to use a block off plate on my offy intake when I am using the EFI headers? I am pretty sure I do because the exhaust doesn't connect straight to the intake manifold anymore. Does anyone have a part number or a place where I can locate one? Thanks

 

No special block off plate is needed, the Offy intake just has two threaded holes for vacuum connections [brakes, tramsmission, whatever]. All you'll need is a pipe plug to seal off the EGR port on the rear EFI exhaust mainfold [get one at any hardware store]. You might need a couple of hose barbs to make the vacuum connections to the intake, or if you're not using them just plug with bolts.

 

don't your also have to plug off the oxygen sensors too. where can you get 18mm by 1.5 threaded plugs for them? the egr port takes a standard 3/4 inch pipe plug after you unscrew the egr fitting

 

after alot of looking around i found the18 by 1.5 threaded plug to plug the o2 sensors on the efi manifolds,
that I just installed on my 78 pickup, at my local muffler shop