[4mula73]

I've decided to use an iron intake on my 400 build over a Performer. I have a spare casting no. 495106 intake to use. It is the style with the EGR bulges on the bottom. I won't connect EGR. Is there really any difference in performance between these and the earlier 68-72 intakes? I think HPP did an article on this years ago, but I wanted to see if any of you had any firsthand experience or insight. The build will be fairly mild. 400 .030" over, XE262, 8.5-8.6 CR, mildly ported 6X-4s. The main reason I want to use the stock intake is for the "sleeper" look. Or is the Performer a better choice than the 495106?

[Rocky Rotella]

No flow difference, but the '73-74 is definitely heavier. And it requires a deep-center valley pan.

[Cliff R]

About 200 pounds heavier!

Seriously, they flow just fine as Rocky mentioned, but really ugly with all that gear hanging under them and EGR on the side.....Cliff

[steve25]

And the added bottom mass of the manifold even with the deeper valley pan does not pass thru as much air as the non EGR set up. as a result the manifold does run hotter and with todays alky spiked fuel can make for tuning / running problems at times , not to mention the slight power reduction from the added heat.
I would plan on blocking the exh crossover and swapping over to a electric choke if need be.
If your hood scoops are not open already, I would plan on doing that and ruuning the air cleaner set up to have them feed the carb.

[4mula73]

Originally Posted by steve25

And the added bottom mass of the manifold even with the deeper valley pan does not pass thru as much air as the non EGR set up. as a result the manifold does run hotter and with todays alky spiked fuel can make for tuning / running problems at times , not to mention the slight power reduction from the added heat.
I would plan on blocking the exh crossover and swapping over to a electric choke if need be.
If your hood scoops are not open already, I would plan on doing that and ruuning the air cleaner set up to have them feed the carb.

I plan to eventually open the hood scoops and use a RA air cleaner. The car will be driven on some colder winter days, just not in ice or snow. Is the electric choke still a better choice than the heat choke for this?

[Blued and Painted]

Yes. IMO

[4mula73]

Is there a specific way to block off the EGR? Or should I just put it on the side of the intake and just not connect it to vacuum?

[android 211]

HPP dynoed a late EGR intake with the D shape secondary holes and found no difference between it and the earlier intakes. The D shape reduced reversion into the carburator. The 73-74 intake should make the same power as earlier intakes. I have a car with a electric choke on the Rochester. It starts the car cold fine but if you drive it down the street only a short distance then turn it off getting it started again can be difficult. I prefer the choke on '67-72 cars.

[Ben M.]

Originally Posted by 4mula73

Is there a specific way to block off the EGR? Or should I just put it on the side of the intake and just not connect it to vacuum?

You can make a plate to block it off, but I just connect the valve up and disconnect the vacuum line.

[78w72]

Originally Posted by android 211

I have a car with a electric choke on the Rochester. It starts the car cold fine but if you drive it down the street only a short distance then turn it off getting it started again can be difficult. I prefer the choke on '67-72 cars.

i have a q-jet with an elec choke added & have some of the same problems you mention on restarts. it starts great in the cold (< 45*) but the restarts are kind of touchy. mine is a fresh rebuild from cliff on a fresh engine so im still working out some bugs on the choke setting & idle tuning etc. i have a 78 t/a with the same q-jet but original hot air choke & it starts & restarts great in cold or hot weather.

[rexs73gto]

I have a performer RPM intake & use a 79 301 Q-jet that I've went through & played with similar to some of the mods like cliff does & I have an electric choke on it. I like the elec. choke as once I got it adjusted correctly it works great & the car starts cold or hot better then it ever did, except when it was brand new in 73-74.

[post toastie]

you can also use a 72 intake that doesnt use an EGR but heat crossover is the same.

[4mula73]

Thanks for all the help! I started sandblasting the 495106 yesterday. I'll just stick with the heat choke for simplicity's sake now and see how I like it as for the EGR, I'll connect the valve and leave it unhooked. Thanks again

[4mula73]

What should I do about the EGR ports in the plenum floor? Should I try to fill or plug them? Or does it not make a difference?

[steve25]

I would drill and tap them for a allen set type pipe plug.
and during the tapping process leave enough uncut threads to really lock the plug into, and some red Loctite would not hurt eitheir!

[zeebo]

id like to see if one could modify a 1972 iron intake for the hot air style choke like the 73-74 intakes..that way you get no egr, and the tailoring of the choke much better than the divorced choke style..anyone ever modify one for this???

[android 211]

As long as you have the '72 choke on the crossover passage you can use an older Rochester. I think the rod is even the same. For some reason they rotated the little coil device 90 degrees. Used a '72 intake with a '71 Rochester on a 400 with 6X4 heads; car still runs great almost 10 years later.