The Stovebolt Site Forums The Shop Area The HiPo Shop Headers for 350 sbc in 56 gmc

I picked up a 1956 GMC 3/4 ton with no engine .....dropping in a 350 sbc and I am not sure which headers will fit with no clearance issues on the steering box...I have seen block huggers but with no experience with these I wonder if anyone has had success with this problem....thanks

Order for a 56 Chevy from Summit, Jegs, Speedway, or probably Classic Parts will have both shorty or full length. DO NOT order for a GMC or you will get Pontiac headers.

I believe coilover is correct. Every one of the speed/custom aftermarket places has headers for '56 chevy 1/2 ton and up headers. Try to find headers for a '62, that's a different ballgame altogether.

Generally headers create more problems than they are worth, some require special spark plugs or you can't get the wires on. Others burn the wires, some you have to loosen or remove the headers to get the plugs out. Most leak because the bolts loosen up. And many have a tinny sound. Also, you probably won't notice any appreciable performance with a stock engine.
Get some stock rams horn manifolds which will last forever or get a good aftermarket set made by Dorman. Jegs sells them.
Fred

Rams horn manifolds look cool too!

X 3 on the Rams Horn. Speedway even has them in stainless steel. Several studies show them to be more efficient than cheap headers.

The only measurable gains I've ever seen on a dyno run when using headers were on race engines at high RPM, using equal-length tubes for every cylinder. I don't know of any street headers that are built that way. For best results, we also had to calculate the length of each individual intake manifold runner and include that in the overall length of the flow from carburetor to exhaust collector. By adjusting the total length of the intake/exhaust column, an improvement in torque for a specific RPM range could be dialed in. Rams' horns will usually provide more torque over a wider RPM range than custom-built headers at any normal street RPM, so headers are just eye candy to impress the gawkers at a car show. They have no practical purpose on a street machine. Block-huggers with their short-radius bends and unequal length tubes are really a giant leap backwards.
Jerry

nj56gmc'

This article in Super Chevy presents a different point of view, describing the horsepower and torque gains from properly sized headers at street RPM as "amazing":

http://www.superchevy.com/how-to/49178-headers-power-increase/

The article says in part:

"Look closely at the two torque curves and you will see a spike of 53 lb-ft of torque at 3,400 rpm while the 3,200-rpm line reveals a torque increase of 26 lb-ft of torque. These are amazing numbers that average more than 26 lb-ft of torque between 3,000 and 3,800 rpm. "

It also helps to know that spark plugs in the same heat range are available in a variety of lengths. These shorter spark plugs are in common use as original equipment on many vehicles and have the benefit of keeping the plug boots and wires farther from the headers. On the 350 sbc engine in my '32 Ford roadster street rod I've had the same spark plug wires installed since 2003 and in about 22,000 miles of driving with headers there have been no issues with cooked wires/boots, header leaks, or any other problems.

As stated by others headers are "eye candy" in addition to the other benefits, especially the stainless headers that turn a very light straw yellow from exhaust heat. Tastes obviously vary but I appreciate "eye candy" whether of the human or automotive variety.

Those amazing extra 26 lb-ft of torque from using headers likely also contributes to an equally amazing extra 26 degrees of heat inside of the cab. Great for winter racing I suppose.

Whoop-de-doo! I've seen that much torque change by adding or removing a couple of degrees of ignition timing, and I've seen it on my own dyno, not a Google search of some archaic magazine article!
Jerry

Hi Carl,

For the first 5 years (1965-70) that I owned my now restored '36 Chevy PU I ran it as a sbc powered "rat rod". The engine had home made headers that I made copying the Doug's Headers "Tri-Y" design in a quest for streetable torque. There was no unpleasant cab overheating, even in summer time because there was good air flow through the engine bay..

In my experience in the hot climates where I have lived header equipped sbc engines in well ventilated engine bays don't cause any problems. No exhaust leaks, no cooked plug wires, no plug access problems and no cab overheating.

The performance gains are documented in the magazine tests. The example I included documented torque increases of 26-53 lb-ft, a very substantial gain. In street driving torque is what we feel seat of the pants, not horsepower. I'll take it. Others may say "no thanks".

The "eye candy" benefits are questionable, depending on personal preference.

I go to very few shows and cruise ins but at the ones I do go to headers are very popular so they must have some kind of appeal.

Many of the vehicles that I have worked on that had headers had some of the issues that I mentioned. I have also encountered
starter heat soak issues. In those cases the installation of a mini-starter cured the problem. It's about personal taste. Quality, price & design are also factors to be considered. Many aftermarket parts don't meet standards, headers are only one of them.
Fred

"Quality, price & design are also factors to be considered. Many aftermarket parts don't meet standards, headers are only one of them."

Good morning Fred.

My welding job at Doug's Headers was in the summer of 1967, 51 years ago. There is no question that a lot has changed in that time, especially in the realm of finding quality for sale at any price. But working inside a header building facility taught me that headers that actually fit properly and don't leak can be made and I actually have a set on my sbc powered street roadster right now.

One trick I learned at Doug's was to bolt headers to a head and spot heat a dime sized area on a few of the primary tubes to a dull red heat with an oxy-acetylene torch to relieve any stresses created by the fabrication welding. That relaxes the tubing creating a proper fit. On my roadster all it took to create a long term (15 years now) leak free installation was using quality Fel Pro gaskets, stainless steel socket head bolts and lock washers, and re-tightening the bolts a few times at first as the gaskets compressed. No special bolt locking hardware was used, just the stainless steel lock washers. The heads are aluminum Edelbrock parts and I don't know if those are more or less prone to bolt loosening than iron heads.

Since this is supposed to be an information sharing forum it seems like the original poster on this thread might be interested to know that there are plenty of header success stories. There is no question that quality is a little more expensive and harder to find than it once was, but it's out there.