The Stovebolt Site Forums The Shop Area The HiPo Shop Headers vs. Split Manifold

Thinking very strongly about replacing the stock exhaust on my 46 (216) while I've got it out. Anyone have an opinion on which might be better headers vs. having the manifold split. Also, any suggestions on which headers might be better and a source? Love the sound of my split exhaust on my 52, haven't done the header thing, so would appreciate feedback from someone that has been there.

Headers will give you better performance because of the design. The sweeping curves allows the gas and air to enter the firing chamber because any sharp bend in exhaust manifold will cause the heaver gas particles to sling out of the air stream. The better vapor condition the gas retains, the more power and better performance you will get. The problem with headers seems to be keeping them tight. And, they have a tiney sound that some people like, but I don't care for. The split manifold would have a better sound. I have always wondered if headers will transfer heat away from the head as well as a cast iron manifold and maybe have pre-mature valve problems. This is my opinion and concerns, maybe someone can help you further.

Truck Tinker

Excuse my getting high-rise intake confused with the headers. The sweeping bends allows the exhaust to vacate the firing chamber better so your fresh gas/air charge won't be diluted and give you more power. The rest of my last post will apply.

Truck Tinker

the only realy bad thing about headers is thay dont last as long as a split manifold would

Truck Tinker and Old Chevy 46, thanks for your responses. I'm continuing to struggle, as I'm not sure where I can get the manifold split in my area or $$$ cost. I've found a couple of different sets of headers on E-Bay, but don't know much about them. One set appears to be somewhat generic, the others are Fentons. Anyone have any thoughts on what might be the better way to go or any other thoughts on the topic?????

I'm putting a set of Fenton split manifolds and a
offi twin single carb unit on a 235! The headers came from bowtie bits for 260.00, the only thing i didn't like was the threaded ports in them, i'm assuming for O2 sensers!

Bodiman, the sets I've seen have threaded ports in them as well. I've been trying to figure out what they were for, and/or what to do with them. $260.00 doesn't sound like too bad of a price. I've seen some generic no-name ones out on e-bay for around $150.00 but I'm a firm believer in the adage... You get what you pay for.

i put fenton on my 235/3100 last summer and am well satisfied. the ports are to add a heat riser plate to take the place of the orginal one. lamgdons stovebolt on the links page have the plates already made up. i got my fentons from patricksantiquecars.com. the heat plate keeps the truck from stumbling when cold but i have had little trouble with out it and drove my truck in the snow and 9 degree weather over christmas. i did have a little stumble this week when it was about 30 degrees and rainy. ron

you should be able to have yours split pretty cheap. all it takes is a grinder, a small piece of 1/4 inch metal plate and someone that can use a welder and cutting torch. it took my brother less than an hour to do mine. i would eventually like to get the "real ones" but i couldn't beat the price and it sounds great!

I have fenton's on my 52 with a 235 in it,, has dual smittys, love the sound, been on for 7 yrs or so. no problem,,, regards,,Fred

Okay, I've found a guy here in town that will split the manifold for $60.00. Alot cheaper than headers. Now my question is do any of you have any thoughts on Glass-packs versus turbo mufflers, pluses or minuses on either side from someone that's been there??????? The same guy that is splitting the manifold will do either system from the manifold back to the rear of the truck with duals for $245.00. That sounded pretty reasonable to me?

glass packs will burn out and change the sound, ( read loud). the best i have seen and read about are flowmaster you can pick the loudness and tune the exhaust. go to www.jegs.com they have them and the prices. ron

Thanks We B Old. I kinda like the loud stuff, (within reason) but my wife and neighbors would probably appreciate the flowmasters.

There are a few companies that sell Flowmasters on ebay all the time too.

There are a few header manufacturers out there that make cast iron headers. While they don't flow quite as well as tubular headers, they still flow a lot better than iron log manifolds, and they seal as well as the manifolds. So I don't think you will have leaks.

Splitting the manifold will have advantages similar to the smooth sweep Fentons but would be just a little shy of the Fentons power making. And I'm sure uncorking the exhaust with a dual exhaust will go a long way to adding power and torque.

For mine, I would like to get a pair of Fentons, run dual exhaust exiting out the sides in front of each rear tire, and a pair of Superturbo mufflers. I like the silence at cruising speed and the aggressive tone at WOT.

And if I change the exhaust, then I'll want to change the intake and use a modern 350 cfm Holley 2-barrel.

It's the "while you're at its" that will make this pricey for me. I guess I'll just collect the stuff and do it when I have it all.

Fred, nice truck. Looks like mine! But no pictures of your engine with the Fentons on it. Would you mind posting or sending a pic? I'd like to see it.

I have a picture of Fred\'s headers.

I have Hedman split headers and Cherry Bombs on my 64 292. I just had new tailpipes put on it. I like the sound. As soon as I get the manifold gasket replaced (hopefully today) I plan to get a recording of the exhaust sound.

There are recordings of the exhaust with open headers and the glass packs at this location:
http://www.chevyasylum.com/64c10/64c10_11.html

This is both sides of the spilt headers exiting on the driver's side of the truck. The new tailpipe arrangement has one side coming out each side, in front of the rear wheels. It sounds pretty good from outside the truck...I'm not sure if I like the sound from inside, tho. But I need to fix the manifold leak (exhaust port) before I can decide.

That's another problem with headers...sometimes it's hard to get them to seal properly.

That sounds good. So you have Hedman headers for a 292? That wouldn't fit a 235, would it?
How much were they anyway?

I know the Fentons will fit, but I'd probably get them ceramic coated so they don't get rusty. And I like the red you painted the engine too. Since my truck's bright red, I think I should go with red for my engine too.
And I really like the red valve cover too. I was going to go with chrome, but the red of yours looks really good.

I think maybe split exhaust, headers, and repainting my engine will be this year's big project for the truck. Maybe also wheel bearings. I don't know if I can do the Holley carb conversion this year though. That's easily another $500.

Does the Stovebolt engine use a common gasket for both the intake and exhaust? I'm pretty sure it does, but I have not torn into a Stovebolt yet.

Thanks for the pics!

Yeah..Hedman part number 27840. I can't seem to find 'em on Summit's or Jeg's sites to check pricing, but iirc, they were about $120.

I'm pretty sure they wouldn't fit a 235. I couldn't find any Hedders (Hedman's spelling) for 235s on their website. You may be stuck with Fenton's...or maybe Clifford's.

The 230/250/292 uses a single common gasket. I'm just about to put 2 Fel-Pros in mine back-to-back, as soon as the motor cools down a little bit. I do this on all my "twin-four" motors so that I have the metal side facing the head AND the header. Works pretty good.

Funny about the valve cover thing. One of my projects for today is to replace that red one with a chrome one. I've also got a coupla noisy valves, so I was gonna adjust things up while I was in there...but I gotta quiet it down a bit with the manifold gasket before I start that so I can hear myself think...and the rocker ticking.

Btw, I added the Offy manifold and Carter carb for about $350 combined. I found a Carter that had been returned to a speed shop as "defective" and got it for $100. Once I backed the idle mixture screws off a little bit, it worked fine. They were screwed all the way in...completely. No wonder it was "defective."

Ya might try Kansaskustoms on the search bar.

Well, I got the manifold gasket replaced today. I got rid of the exhaust leak on #4. It moved to #1. So I fixed that. Then it moved to #3. I said, "I've had all the fun I can stand, bein out here in the cold and wind." So I shut the hood and left it sittin for the nite. I should have some free time tomorrow morning, so I'll see if I can shut up the #3 leak.

I may eventually get a recording of the exhaust sound. Ohh...there's no H pipe on the split exhaust. So what I record on one side will be 3 cylinders. I'm thinkin that I might take it back to the muffler shop and have an H pipe installed. The split sound isn't bad. I'm not sure. I'll have to drive it around some and see what I think. I'll get a chance to do that tomorrow afternoon, since I have a meeting with a manager at work...which means I have to drive into town. We'll see.

Flowmasters take away from the whole "split" sound.The real trick is to get some Steel Packs but they are hard to come by.I personally like when glass packs burn out,I even go as far as break the glass my self-drive around town and get nice and hot,go home and run a water hose in your tail pipe!
On glasspacks there is a loud/quiet directions(just flip around).

If no one has said it yet, those threaded ports are for manifold heat tubing.

ChevyAsylum, the crossover does act to remove some of the raspiness from the exhaust, and it also can add some power, due to cross scavenging that otherwise wouldn't occur.

Car Craft I think it was, did some testing with a V8 engine, and there were some very clear differences between no crossover, and X, and H crossovers.

The X-crossover was the best at cross scavenging and would build big torque from idle to about 3500 rpm. Then from 3500 to 5500 rpm, the H-crossover made better power and torque, they theorized it was because the X would seem to over-scavenge at certain engine speeds...(whatever that means). And then again at rpms above 5500, the X was clearly superior.

I don't really know the impact of "cross-scavenging" on a straight 6, but on a V8, it does help. It couldn't hurt to try it. Summit Racing had the best price going for an aluminized X-pipe crossover kit. I got one for my IROC-Z Camaro when I built my custom dual exhaust, and it's really nice. Worth every penny.
Up to 3500 rpm...isn't that the vast majority of a stovebolt's operating range?

I'm going to a big swap meet this weekend. I will be looking for a pair of Fentons...but they are quite rare. I once found one, but its twin was missing.

If I find a pair, I'll be buying another X-crossover from Summit this summer.

Magnaflow is another good muffler,They sound more like the glasspacks.Doesnt Fenton make cast iron headers?

Hot Rod Dad, just FYI, over-scavenging means the exhaust is pulled from the combustion chamber so effectively that it also sucks part of the intake charge out during valve overlap.

As far as glass packs vs. mufflers, I have to say mufflers all the way. I ran glass packs for two years, and by the end I was almost deaf and didn't even realize it. That sh*tty-blown out sound really sneaks up on you. I had a muffler shop do a dual flowmaster exhaust for me awhile back, and they only charged $90 per muffler (so 90 for a single exhaust, or 180 for dual). That price included labor and all parts for a custom job, so I would think you could do better than $265 and supplying your own parts.