what year truck or engines do i need to look for to find a set of efi ex manifolds?going on a 78 300.

 

Ex manifolds?

If you're meaning the split EFI manifolds...1992+ for sure....Maybe a 1990-1991 has'em....

 

I'm pretty sure that '87 and later 4.9's were efi so you should be able to find the split manifolds an any truck '87 and later.

 

I have a new set laying around I ended up not using. I can email you some pics if you want.

 

If he is not interested I may be.

Jim

 

thanks for the offer but im just making future plans for a rebuild down the road and wanna know what to look out for.

 

The EFI manifolds are from an 87 to 96 truck. I don't think there are any differences amongst the years.

 

are these just bolt on or is there any other upgrades that have to be done?

 

Yes and no.

The manifolds themselves are a near direct bolt on. They bind a little bit with the stock intake, so some grinding may be required. If you have a good hand-held or bench grinder, it'll take about 5 - 10 minutes is all. Mock them up on the engine before you install them and you'll see where they bind.
The EFI manifolds have 3 extra bolt holes on them for ease of installation (you won't be able to use them since you won't have the 3 extra bolt holes in your head). One of them had to be ground off on mine since it was binding with the intake.
Also, some extra material on one of the runners had to be ground off because it was binding with the intake.



(You can also see one of the extra bolt holes on the manifolds in that picture).



Secondly, ALL of the emissions components tie in with the stock exhaust manifold. If your truck has an EGR valve, AIR pump, etc., you'll have to remove all of it because it won't work anymore unless you want to get really creative.


Lastly, you'll need to keep in mind that the stock exhaust manifold has a provision to provide heat to the intake. This heat helps with fuel atomization and eliminates bogs and lean spots. The EFI manifolds have no such provision.
A common way to fix this is to apply coolant heat to the bottom of the intake. A lot use a plate like this that bolts in place of the exhaust manifold.




You can make your own, or get them here: Home Page

You CAN run without it, but you may notice some performance loss under certain conditions, especially when its cold outside.