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I picked up an Ellis Dual Power intake for my 54 GMC 630-50 awhile back. It fits the 426/503 GMC 6s and uses 2 SAE #3 single bbl carbs - shown in the picture with adapters for Stromberg 97 type mount.

Does anyone have any experience with these or other aftermarket intakes for big trucks? Do they add any power?

http://s1061.photobucket.com/user/abhadurihauck/media/IMG_0201_zpsca960aac.jpg.html

Yeah,an engine is virtually an air pump,so adding another carburetor,was the birth of hot-rodding.Carbs,(as we all know),use volumes more air than fuel. It would also help the "Big 6's pull a little better on the hills,maybe even gain a gear.(With the help of dual exhaust).I know Ellis made split-exhaust for some Diesels..But this dual-intake for a vintage "Big 6 Gasser" is "New news"! Do you have any pic's of the 630?? Please keep us posted! Welcome to the "'Bolt"!!

There's a truck for sale in Kansas that has one of the Ellis manifolds.

http://www.commercialtrucktrader.com/listing/1952-GMC-10k%2B-113365067

More carburation helps at higher RPM and at full throttle. At lower RPM, more carburation can actually cause a flat spot. If you were going to drive it like we did over 50 years ago, it would probably help. My gas GMC was rated at 232 HP and with more carburation, it did better than that. And it ran circles around 671 Detroits. But for a vehicle that you are not going to run full throttle, I would say that all you have is a good conversation piece. These were low RPM engines. And if you run them at higher RPM, they won't stay together.

Thanks for the responses. Crenwelge, tell me more about your GMC. What engine did it have? How many RPM were you running? My 503 is rated for 181HP at 2800 RPM. I understand the loss of low RPM power but its a fire engine so you're trying to be quick

Has anyone run a manifold like this with the stock exhaust manifold?

WetWilly, here are a couple pictures of the truck:

Now:

http://s1061.photobucket.com/user/abhadurihauck/media/IMG_0127_zpsbba7f0aa.jpg.html?sort=3&o=10

When almost new:

http://s1061.photobucket.com/user/abhadurihauck/media/Engine23_zps9def5d21.jpeg.html?sort=3&o=3

I have one of those manifolds, too. Everyone should have one. Will give more HP, at the expense of low end torque, fuel consumption, make sure to have a tanker trailer. Great trucks, though. Usually have juice brakes.

Good opportunity for Cummins repower w/ a Brownie or 4500 or FSO.

Ed glad to hear you like yours. What truck/engine do you have? Do you have a different exhaust set up too?

Mine was actually a Blue Chip 550. It was titled as a 56, but it was born with a 370 engine that did not become available until 1957. The 503 was still available in the Blue8 Chip series in the 630. The 650 series had the Olds V8. Chevrolet then introduced the 348 and a little later the 409 which were also high RPM engines and dominated the gas market for quite a few years until the first oil embargo totally killed the market for gasoline powered trucks to gross 80,000.

https://plus.google.com/10819770718...4965267442&oid=108197707187186692269

The engine was actually a 371 Olds engine with lower compression and rotating valves. The original carburetor was a Holley teapot which rated it at 232 HP. Not long after the picture was taken, I added a Neway drag axle to it. The intake manifold was actually Oldsmobile with an adapter to accept the Holley. I removed the adapter from the Olds manifold and installed carburetor from an Olds 394. I had forged flat top pistons instead of the dished pistons that GMC used. I actually pulled a grain trailer more than pulling a tanker. I got about 100,000 miles between overhauls and drove it about 125,000 miles a year. I made sure I never let the RPMs get below 3600 and usually downshifted at 3800. I up shifted at 4200 but letting her go to 4400 to get a run at the next hill was common. I averaged around 2 miles to the gallon loaded and about 2 1/2 empty, but gas was only 20¢ a gallon back then. Hauling a load of grain 250 miles paid about $125 in those days and it took about $25 worth of gas.

Crenwelge, thanks for the info, that is a neat picture. First hand experience is always great to listen to.

53GMC630,

I don't have one now, just got the manifold. Have '37 GMC T-18HD w/ 4-53T, RTO-610, Brownie GMC 3500 HD running gear, power steering, 22.5 wheels.

Ed,

10-4. That 37 sounds fun. Detroits and Roadrangers are a good combo, you must a gear for every mood with a brownie behind the 10 speed!

Alex