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I have a stock 86 Trans Am with a T5 transmission. I am removing the 305 V8 and installing a 1969 Corvette 350 / 300 HP V8. What headers would be the least expensive and best fit and still preserve the 300 HP? I do not have mufflers or catalytic converters. I do not have to meet any emissions standards. I do not care about fuel economy. I like loud. It will go fast enough. I have no plans for future increased horsepower.
The 305 I am removing is a carbureted engine with stock exhaust manifolds. Will the cast iron 305 exhaust manifold bolt up to the 1969 Corvette 350/300 hp engine, and without sacrificing horsepower? The 350 also has a 1979 Corvette Quadrajet carburetor and intake manifold. What do you think?
And they won't fit any block with a driver's side dipstick, and won't bolt to many heads due to the bolt pattern.
True! Found this out when I put Vortec heads on my 87 and tried to use the stock TPI manifolds. There is MUCH to be gained with a good set of headers and exhaust system.
Dyno Don headers fit the best. They are not particularly cheap.
But if you hate yourself and have lots of time to frustrate yourself then by all means there are other options.
GD
I LOL'ed at this one.
But if you want it loud and sounding right, go with long tubes. You will sacrifice some ground clearance and like GD said, most cheap ones are going to require some mechanical persuasion.....basically you'll have to determine how much your time is worth. I have a set of shorty hooker headers which do me fine for now, but a friend had a 3rd gen with LTH which was definitely louder with no work done
That's great to hear about your friend, BUT.....what long tube headers did he use? That's what I'm looking for. I'm looking for specifics. Who has had a good experience with ebay long tube headers, which ones, and what, if anything, they had to do to get them to fit the engine and engine bay? I am going to custom build the exhaust from Y pipe back, with no cats and no mufflers, so all I care about is getting the headers out of the engine bay, without modifying anything.
If only there were a couple threads explaining the merits of the available headers that will fit our thirdgens, or a 10 page thread full of pictures and info about the pros and cons of Ebay Longtubes, that a person could read thru and get some good advice about headers... I mean they could even be sticky'd to the top of the exhaust forum so that they'd be super easy to find... The only thing worse than not having a ton of informative info, might be having a ton of informative info, and not having anyone ever read through it before asking for info that's already covered in prominent threads...
I mean not to be a dick or anything, but it's not like there's anything new under the sun. A person can easily find too much info to absorb and remember with a simple search. Maybe the answers to your questions are already in a couple of these indepth threads...
I have eBay stainless mid length on my car. Absolutely in no way would I recommend them! Super pain to install all the way down to having to enlarge the bolt holes in the flanges so bolts would fit and the y pipe has to be much less than optimal to have any ground clearance. Also required special "shorty" header spark plugs and all 90° boots and a couple heat socks to not burn the wires. Spend the money and do it right the first time. I wish I had....
Thank you, "Supreme Member". I'm just a "junior member" (lower case), who doesn't even know what or who "sticky" is, and, from the sound of it, I wasn't sure I wanted to know. I am older, with a bad memory, or I wouldn't have to be asking my dumb questions that have obviously and apparently already been answered by something or someone called "sticky". I feel like a kid with his hand up to ask the teacher a question, only to be told to go to the library and look it up. Well, I guess I'll just have to do that.
By the way, "Supreme Member", do you just happen to have a simple answer to my question: With your obviously vast knowledge of all things "third Gen", regardless of what "sticky" says, what is your own personal opinion about my situation? What would you do? With my obviously "half vast" knowledge of anything "third gen", I would really like to know.
If you cant get some DynoDons.. Get Hooker 2460 headers and a Dougs D901 Y-Pipe to match up to it. For around $400 or a lil less I think you will be happy.
Thank you all for your suggestions, sincerely, this time. I did read all of the "stickys' Drew referred to before I posted my question. I was just messin' with him. I happen to agree with him, actually.
That's why I'm here. I think Drew has the answers. I have spent hours and hours on line and on the forum, but still haven't gotten a specific answer to the "cheap" header question. I know SLP, Hedman, Dougs, Hooker, Don, etc., but I'm just looking to see if any of the cheap imports have copied the "good" stuff close enough to be worth a try.
In my opinion, somewhat limited experience, I know the SLP headers fit. The Dyno Don headers are pretty much an improved clone of the SLPs. The Hooker 2460s are a decent header at the low end of the cost spectrum. Below that, the Ebay long tubes are probably worth a few minor headaches for what they offer in performance and value. Most of the no-name shorty/mid length headers you see on Ebay are copies of the Flowtech or Dynomax shorties. As a general rule they have small primaries and aren't the best header.
Seems like back in the day, most people ran SLPs if they were serious and Edelbrocks if they wanted to save a bit. The Edelbrock headers sorta took a character assassination due to the D shaped transitions into the collectors/Y-pipe, while other headers like the Hooker's with AIR tubes got more popular because of their superior Y-pipe, along with the similar Hedmans. The Hooker 2460s have never been all that popular because they don't come with AIR injection tubes, and the Y-pipe necks down, but they can be had really cheap.
I've got a pair of SLPs on the shelf, and a pair of 2460s, if I didn't have two sets of headers already sitting on the shelf, I'd order a set of Ebay long tubes. For the money, I'd think it'd be hard to beat the Chinese long tubes, but if a pair of used SLP, Hooker, Hedmans, etc popped up at a reasonable price, they're all a bit more of a known quantity.
Thank you, thank you, thank you. How can I tell if the headers are made for my 86 Trans Am. If they are advertised to fit 3rd gen, do they all fit ALL 3rd gen, any year, and both Camaro and Trans Am and any 350 block? Again, I'm sorry to be such a dunce, but I am new to 3rd gens. I was thinking everything bolts on to everything, but I do have a 1969 350 Corvette engine, so I don't know any details. Is there a particular ebay LTH you would try?
Well...I got it all sorted out. I called Matt at Gearhead Garage in Gilbert, AZ. He has done a ton of 3rd and 4th gen stuff over the years. He recommended headers through "speed_daddy" on ebay. He has had a lot of success with their headers. They are chrome-polished stainless steel 1.75" inlet to 3" collector, medium-tube (instead of long tube that I was originally looking for) $75.68 delivered to Mesa, AZ. Matt can fab the "Y" pipe (2.5"x2.5"x3" outlet), 3" exhaust to rear split to 2.5" dual tail pipes for around $400. I ordered them today and was promised free delivery by next Friday (1 week).
I am removing and selling the original, complete, good running, 305 carbureted engine, minus the intake and carb (stolen while in storage). They left the intake gaskets? If anyone is interested. And, yes, I know there is a place here somewhere to post things for sale, but I haven't gotten that far with my "junior member" level of knowledge. I've been a "senior" for so long, its nice to be called a "junior" for a change.
Here are the specifics:
speed_daddy
STAINLESS RACING MANIFOLD HEADER CHEVY/PONTIAC/BUICK 265-400 V8 SMALL BLOCK SBC
ebay item # 202406673614
Maybe I'm missing something... But, I'm going to go out on a limb and say those probably aren't going to fit (well).
Take a look at the pic above of two sets of thirdgen headers. Note how the Driver's side header dumps between cyl #5 & #7?
Now look at some stock manifolds... Check out how the driver's side manifold dumps between 5 and 7.
I could post another photo, but suffice to say the stock driver's side down pipe, crosses under the engine between the oil pan and crossmember. That's where GM made room for it. Now sometimes you can route the exhaust differently, for example most long tubes dump at the rear and with a custom Y pipe, you can follow the transmission tunnel, but it's more work to get where you're going.
Most bolt-in headers use a Y-pipe that follows the stock routing. The Ebay long tubes come with a Y-pipe that runs down the trans tunnel and joins up near the rear of the trans. If the Ebay item # 202406673614 headers don't hit anything, someone will still have to fabricate a downpipe. What you'll run into with dual anything, is that GM didn't design thirdgens to have true dual exhaust. Dual cats Y together near the trans, the "dual resonator" setup in the early 80's Y's in front of the cat, and splits again over the rear axle. Getting two 2.5" pipes over the track bar and rear isn't exactly impossible, but it's going to be a lot more complicated than simply buying an exhaust that actually fits. There's not much to be gained with duals over a good single either. But those are all little details covered in dozens (Hundreds? Thousands?) of threads over the years.
The pics above show how the long tubes designed to fit a thirdgen are routed. There's not a lot of clearance, or room for error. As mentioned these are all over Ebay for under $200 a set -
eBay item number: 283379338544 for example. The reason they mostly work is because the Chinese bought a $1200 set of custom headers, and then reverse engineered them.
Thanks, Drew. I will talk to Matt and take a good look at your information. He is the one who has to make it work, since he will be installing and fabricating the exhaust system. He has done a bunch, so, like you, he will be more able to ascertain if he can make them work or not.
Again, thank you, Drew. I hope you got a laugh from my initial response. I had a longer, and funnier one, but my wife wouldn't let me send it. I was going to have the exhaust custom fabricated from the collectors with 2.5" pipe to a custom y as in your last photo, then as a single 3" over the axle, then dual 2.5" or 3" for looks.
The other alternative is to run true 2.5" duals from the collectors to an X pipe then duals all the way back. I'll check with Matt again about the headers.
Ok. I got the ebay headers from Speed-Daddy. They look really good. They fit the 350 block perfectly, with good access to the spark plugs. I have not yet installed the 350 into the Trans Am, but after doing some initial measurements, it looks like they will fit. However, Drew has a good point about the driver side configuration. The stock configuration dumps down mid block to the stock crossover pipe. These ebay headers dump down towards the rear of the block and pass between the clutch slave cylinder and the firewall. I will take photos of the progress. The inlets are 1.5"x1.75" oval to a 3" collector. The stainless steel polish and welds look good.
Not to start trouble, but "TPI" factory manifolds with dual cats and 3" cat back will support 300 HP.
No trouble, Greg. You are right. I did some research that supports your statement. Obviously, headers are an improvement, but not necessary for 300 HP. I'm doing the headers for three reasons:
1. They look cool. (That should not be the main reason, but it is.)
2. They sound cool. (That, too, should not be a main reason, but it is.)
3. They give improved power and energy efficiency. Yah, well, ok, but I'm not racing, and I don't care about gas mileage. If I did, why would I want such cool looking, cool sounding muscle car in the first place.
the stock 1 7/8" total id of the entire log manifolds is incredibly restrictive.think of a set of 1 5/8" headers,each tube is 1 5/8" x 4 each side.
so in comparison,the stock manifolds connected to 4 cylinders share 1 tube that is about the same size as 1 tube (per cylinder) on a decent
set of headers. so 8 unrestricted paths 1 5/8" each or 4 cylinders a side sharing a 1 7/8" path merging into one 2" or less collector (per side)
its like comparing a straw's diameter to a coke can's diameter
True! Found this out when I put Vortec heads on my 87 and tried to use the stock TPI manifolds. There is MUCH to be gained with a good set of headers and exhaust system.
If you cant get some DynoDons.. Get Hooker 2460 headers and a Dougs D901 Y-Pipe to match up to it. For around $400 or a lil less I think you will be happy.
I know this is an old post but you're the third person suggesting this combo if Dyno Dons can't be afforded. I am leaning towards this combo for my IROC. Thanks
I know this is an old post but you're the third person suggesting this combo if Dyno Dons can't be afforded. I am leaning towards this combo for my IROC. Thanks
Its still a good combo but the doughs Y pipe merger sucks get some 3" pipe and cut and weld it up proper.
Yes the Y-Pipe merger into the main exhuast is a bottleneck. Flowmaster makes a better merger to merge into a 3in pipe. Simple for an exhaust man to cut the Dougs merger and add this. I put the flowmaster merger on mine
Yes the Y-Pipe merger into the main exhuast is a bottleneck. Flowmaster makes a better merger to merge into a 3in pipe. Simple for an exhaust man to cut the Dougs merger and add this. I put the flowmaster merger on mine
Did you use one of Flowmasters scavenging Y Pipes? How do you like it?
05-15-2019, 06:09 PM
