So, I've gotten enough money saved to get EFI manifolds, two Flowmaster mufflers and get a true dual exhaust fabbed up. However, I don't have the cash to put on an aftermarket intake/4bbl carb. My question is, since the stock intake and exhaust manifold bolt together, and I can't get a new intake at the moment, would I still be able to use the stock intake with EFI manifolds?

 

10-4, no worries other than the loss of exhaust heat to the bottom of the intake.

 

Alright. And to address the loss of heat to the intake, does somebody make a heated plate, or would I have to fab up some kind of plate to put on the bottom of the intake to prevent icing?

 

Icing issues can be solved with a stock temperature controlled air cleaner. Many run at 100 deg. Most have an internal thermostat using engine manifold vacuum that controls the damper door. It won't vaporize fuel as quickly in cold weather but mine all worked well in New England.
Happy New Year
rikard

 

carb heat has been discussed many times on this forum. use the Search and look. using the efi manifolds means loss to heat to the stock air cleaner, so that heat has to come from another heat source. you will find some have fabbed a method of introducing hot coolant to the stock manifold. also look at posts from Abandoned Bronco on this subject.

btw: most will recommend using Mr Gasket #260 set over the fel-pro set. also another recommendation is using studs for installation.

 

Heya dyingtolive,
The biggest issue I had with installing the EFI manifolds with the stock intake is that they didn't fit together 100%. There's some ***** on the EFI manifolds (not sure what they're for), that had to be ground off. Also, one of the extra hanger loops on one of the manifolds had to be removed. Lay them on the ground and line them up where they'll go when on the engine. You'll see what's in the way and what needs to be removed.
None of what you'll remove will be vital in any way, so don't worry about it. But they won't go together without a little work.

As for the heat source, you'll need to make one yourself.
Use the stock gasket as a template:


(yeah, the top holes are misaligned. My brother made it. =P)


Thread the holes and put some long pipes to clear the exhaust manifolds. I got all the piping from a plumbing store. Just be sure to fully coat and seal all the threads. Some weld them to fully prevent leaking.

I didn't, but it's best to install it while the intake is out. Be sure its sealed up really well.
Also, it depends on what your your engine is, but on some 300s, the smog pump inlet to the manifold is in the same chamber as the heat chimney is. Be sure to plug up the smog port, or coolant will come out.


You can see where I tried to use a gasket to cover plug the smog port in the above picture (the circle in the gasket right next to the large carb opening). It didn't work too well, as the gasket would eventually punch through. If found it a lot better to just get a plug from the plumbing store and install it where the smog pump normally went into the intake.


Lastly, be sure to fully clean out the underside of the intake before installing one of these. If not, the coolant will wash out all the carbon buildup in there and fill your coolant system with it.


Also, I agree with Parr, converting to all studs really helps. Use grade-8 hardened steel, though, or they'll snap. That's no fun, I had that happen.