Looking for some advice here.

I have a stock motor, with headers on it at the moment. I came to the conclusion that the manifold is warped because it leaks no matter what I do out the thermostat housing. And Ive been wanting to replace it for a while.

Looking to see what intake would be better for me, like I said pretty much stock motor, 1972.

I am running a heater choke now, I can change that if I need to be.
Looking at the 3711 or the 7111.


I know the 3711 has the heat choke on it while the 7111 doesn't but looking to see what will work the best with a stock motor at the moment.


Any recommendations?

 

For a stock '72 engine you will not see any performance increase with an aftermarket manifold. If you MUST change it, go with the 3711.

I guess I should ask what manifold do you currently have? And what thermostat housing do you have? I have never heard of a factory iron intake being warped at the thermostat sealing flange, but it is very common for aftermarket chrome t-stat housings to warp and leak.

Personally, I would keep the factory iron intake and work on getting the t-stat housing to seal.

 

The manifold is usually not the problem, the water neck is.

 

I will get the numbers off of the intake.

I replaced the housing 2x. The first one was warped and the second I had milled down straight. It leaks out the front and one of the bolt holes. I tried everything, gasket by itself. Just adhesive, a gasket and adhesive on both sides and it still leaks. I'm so sick of it. Not saying that a new manifold would help any but its the only thing I haven't changed yet.

 

I would use some thread sealer on the bolts and use Fel-pro 35130 gasket. Don't use a chrome waterneck.

http://www.napaonline.com/Catalog/Ca...130_0150269581

 

There is a felpro gasket on there now. I will try the sealant on the bolts. And no it isn't a chrome water neck either.

 

If you do go aftermarket, the 2711 does not have the EGR and is not a hi-rise like the 7111.

 

See if you can find a cast iron water neck, I've had good luck with those in solving troublesome leaks.

 

The 2711 also does not have a hot air choke provision (it's a 3711 with no choke and no EGR). The 3711 comes with a block off plate for the EGR so that's not an issue, plus it has the hot air choke provision.

 

I'm going to disagree with this. Making HP is all about moving air (and thus, fuel) in and out of the engine. The greater the mass airflow, the greater the HP. The OP's engine has headers already, and hopefully a free-flowing exhaust. The stock intake is limiting the benefit of those headers. A good aftermarket intake (ie, a Performer RPM, not the base Performer - which is marginally better than the iron intake) will likely help a lot. Will it be a perfect combination? Of course not. The engine is a system of parts, and all of them need to be matched to the application. A better cam and proper carb jetting is needed to get the most benefit from the headers and intake, followed by larger valves and porting, etc, etc. So long as you're sticking to easy bolt-ons, an intake to match the headers won't hurt.

 

I would look for a factory A4 aluminum intake. Almost as good as the aftermarket intakes and lots cheaper. And you can run HEI.

 

Do you really think so? I was under the impression the W-31 intake was an aluminum version of the iron intake, and if so, it flowed enough air for that engine to make a whole lot more horsepower than a factory 1972 350.

 

Keep in mind that the gross horsepower ratings from 1970 and earlier were made on dynos using dyno headers, no accessories, an optimized bellmouth inlet, and a whole bunch of other changes that did not apply to the as-installed configuration. That's why automakers were forced to go to SAE Net HP ratings starting with the 1971 model year. I put exactly zero credence in any factory ratings from that period. Example: do you REALLY believe that the 1970 W-30 motors made LESS HP and torque than the Toro W-34? If so, why not just install the W-34 motor in the 442 instead of coming up with different heads, intake, and cam? Or, do you really believe that the AT versions of the W-30, with the 285/287 cam, made the same 370 HP as the MT versions with the 328/328 cam?

I think not.