mwoolf

Im converting a 91' 4.9l from efi to carb and dont know what this is or how to get rid of it. I have an 83' 4.9l, would I be able to use the head off of the old and put it on the 'newer' if I cant get rid of this?
thanks

tleach17

Looks like part of the emissions system. What does it look like where it goes into the head? Maybe you can pull it off and install freeze plugs in the hole.

mwoolf

thanks for the quick reply! Im away from it now, but i think was hooked up to the smog pump. I was wondering if I could unbold it from where its hooked up at or somehow plug it up.

tleach17

Its part of the EGR system it is hooked to the smog pump. Are you removing the smog pump?

mwoolf

Yes, my ultimate mission is to switch this to carb to replace my 83', with threw a couple rods. Trying to keep it simple. So want to get rid of as much stuff I dont need as possible.

tleach17

My recommendation would be to see if you can pop it off and see if the holes can be capped. If they cant then put it back on and cap off the holes in it. If that id not possible see about switching the heads.

mwoolf

thanks! Gonna try it next week on my days off

tleach17

Im not sure if the heads can be swapped. They have the same head gasket part #. I would think it would swap over but im not positive. you could remove the valve covers and compare the top ends. and see if the valve trains are the same. Make sure you use the distributor out of the carb engine. The gear is different on the dist.

mwoolf

my distributor is practically brand new from the old engine, so will put that in as well as a fuel pump. Any other things im for getting?

jonquil

It's called an A.I.R. tube. Part of the emission system. The smog pump pumps air through it and into the exhaust manifold/engine (depending on which manufacturers engine you are using) to improve the quality of the exhaust gasses. I removed one from a chevy 350 and simply installed 3/8" pipe threaded plugs into the holes of parts that could not be removed such as the exhaust manifolds. I cut the belt on the smog pump, removed all the crappy rubber pipes and valves on the end next to the smog pump and just let the pump sit there and rust or rot, whichever came first.

When my state began smog testing, I held my breath during the first test. That sucker passed with flying colors. It tested cleaner than my two year old chevy. All I had to do was keep it tuned up and keep the carb in good shape. However, if your state uses a visual test to determine that all the smog stuff is on the engine, you cannot remove any of it. But you can remove the smog pump belt and plug the rubber hoses and go for it. To pass the visual, you have to reinstall the belt for just the test.

Good luck