Does an efi intake manifold need to be level?

I am helping a friend install a speed density 5.0 efi into a '49 Ford. We need to know if the intake manifold has to be level, like a carburated system. If not, how many degrees are tolerable to be off. My thinking is that carburators, and tbi systems are supposed to be level, but multi-port systems didn't since fuel doesn't travel through the manifold. Is this correct?

no it doesnt have to be level, that engine will run fine upside-down, so the manifold doesnt have to be dead on, as long a the fuel makes it to the spark youre all good

Yes indeed, if you could control the oil, you could darn near run a multi-port injected engine upside down.

The only reason Ford EFI intakes were flat on top is hood clearance, otherwise they'd probably be straight up in the air with the TB at the front...Look at the truck intake. Looks kinda like it's standing on end.

I am helping a friend install a speed density 5.0 efi into a '49 Ford. We need to know if the intake manifold has to be level, like a carburated system. If not, how many degrees are tolerable to be off. My thinking is that carburators, and tbi systems are supposed to be level, but multi-port systems didn't since fuel doesn't travel through the manifold. Is this correct?


No it does not need to be level, the injectors work off of pressure. Even the TBI does not have to be level because the fuel is being SQUIRTED into the carb. The TBI is nothing more than a carb that has been slightly altered to have a injector instead of bowls and needs.

Thanks ALOT guys. I really appreciate the fast responses since I am going over today and we are ready for the motor mounts. Thanks again!

Thanks ALOT guys. I really appreciate the fast responses since I am going over today and we are ready for the motor mounts. Thanks again!


No problem and good luck.

You guys did so well this last time that I am going to ask another question. What all is involved in eliminating the air pump(for smog) and all emissions equipment. We have already welded up the rear exhaust recirculator pipe and are ready to remove the pump itself, and all things involved with it. Do we just buy the smog eliminator pulley and not hook up the wiring or what? We would like to eliminate all un-needed solenoids and other wiring involved with emissions. We should be getting a new harness(speed density) so when we do, we need to know how to wire it all properly, but not wire in the un-needed. What all sensors can be eliminated? I know there is a lot of hoses, sensors, and wiring associated with the emissions, but I don't know where it all is, or how to properly remove it and keep the computer working normally. Hopefully you can give me some insight.