[Kopfjaeger]

Question, actually a few of them. 67 SS396 with a 427 bbc. 535hp at the crank, 1 7/8 primaries into 3.5 “ collectors (Lemons).
Owning a 67 SS396 has been a dream since my early 20’s. I’m in my 50’s now. I’m 6 years into its resurrection and I’m formulating a game plan for how to proceed. I’ve deviated from stock in several areas, suspension, fuel delivery (EFI), brakes, wheels, and 5-speed transmission. I’m looking for a fun and spirited vehicle that can hold its own at the track, on occasion. I was planning to run 3” to the mufflers, which ones, not sure yet. I was thinking Black Widow Venom 300’s.

I do plan on a custom exhaust and would like to have the tail pipes exit at the stock location, behind the rear wheels. A 3” tail pipe is problematic going over the rear axle and exiting in the stock location.
Would a 2.5” mandrill bent tail pipe be feasible and not crush exhaust flow?

X pipe or H? I’m also not “ married” to the Black Widows.

Thanks in advance.

Joe

 

[TommyK]

3 inch is no problem and common, tight spots I had are at the axel itself and stock gas tank front corners. Downsizing past the muffler is a very wise decision. Exhaust gas velocity slows as it cools. The cooler temperature at the tail pipes and less velocity means you can have similar performance with a smaller diameter exhaust pipe. Same principle goes for turbo location and spool time as heat/velocity is power. X over H in my opinion and any straight through muffler.

 

[NickeyChevelle]

What is the diameter of the exhaust ports on your heads? Maybe you might want to match the primary pipe size to the port diameter?
"X" Pipe, UNLESS you prefer the pure, sweet sounds of a true dual exhaust on a BBC.
2.5-inch mandrel bent tailpipes should be fine from the mufflers back. Unless you're really serious about the track...

 

[RatchetRay]

2 1/2" tailpipes won't be a restriction at that power level. 3" tailpipes can be done without too much trouble and won't restrict you if decide to keep upping your HP... it happens.

 

[2/75NastyNewbs]

I recently did a full 3” mandrel exhaust. Good clearance everywhere. I brought my local muffler guy the tail pipes and he cut them up and rewelded them. A quality install is the make or break here.

Black widows sound cool but they are loud. Tail pipes will mellow them down some. I have some 250s sitting in my garage. I ended up with the 3” internal dynomax super turbos and I’m very satisfied. No crossover either.

 

[Bob Tiley]

I have Hooker headers with 3.5" collectors, then 3" pipes to the mufflers and then 2.5" Flowmaster tailpipes. Most mufflers have 3" or 3.5" internals. Works good and is fine up to 600hp.

 

[Kopfjaeger]

Yes, the Venom 300’s sound like they can be border line obnoxious, sometimes, which is why it’s important they dump as close to the stock location as possible. What I‘d rather not have is the droning that some mufflers give. Black Widow claims they won’t drone. The 5 speed will help tame the 3.73 gears on the highway but with everything I’ve put into the car so far, having The exhaust drive me nuts on the highway would be very unfortunate.

Joe

 

[2/75NastyNewbs]

Yes, the Venom 300’s sound like they can be border line obnoxious, sometimes, which is why it’s important they dump as close to the stock location as possible. What I‘d rather not have is the droning that some mufflers give. Black Widow claims they won’t drone. The 5 speed will help tame the 3.73 gears on the highway but with everything I’ve put into the car so far, having The exhaust drive me nuts on the highway would be very unfortunate.

Joe

Just for comparison sake, I had the black widow 250s dumped at the axle and it was LOUD. Swapped in some 14” case jones mufflers (magna flow, dynomax ultra flow etc etc knock offs) still dumped at the axle and it was dramatically quieter. Yeah the case is larger with the 300s but there’s no sound absorption material inside. Just those two baffles, if you can call them that.

 

[Lew540]

I would agree with that power level and cubic inches a 2.5 inch over the axle manderel bent (not the 1980s lets bend a 2.5-inch pipe and shazam we now have a 2-inch pinch pipe). A good compromise might be a 3 inch to the muffler and 2.5 inch over the back. Like Bob said above - but also like he said must have 3-inch internals the 2.5-inch internals will be restrictive.

 

[66rat]

I agree that 3" to the muffler and 2.5" out the back would be sufficient in the OP's application. Decision on muffler choice is so subjective, everyone has their own preference. Personally, I'm a Borla fan, I use them on all my cars. However, I would recommend a straight thru muffler design as opposed to a baffled muffler. I decided on Borla by going to test and tune at the race track and listening to various cars. Borla was the clear winner for me, but be warned, they are loud when you stab the gas. Having 2.5" tail pipes will definitely help in the noise department. Next question is the cross over. Again, a personal choice. I prefer the standard "H" design over the "X". The "H" gives the car a more traditional muscle car sound as compared to the "X" design, which tends to give the car a more raspy sound.

 

[Kopfjaeger]

I agree that 3" to the muffler and 2.5" out the back would be sufficient in the OP's application. Decision on muffler choice is so subjective, everyone has their own preference. Personally, I'm a Borla fan, I use them on all my cars. However, I would recommend a straight thru muffler design as opposed to a baffled muffler. I decided on Borla by going to test and tune at the race track and listening to various cars. Borla was the clear winner for me, but be warned, they are loud when you stab the gas. Having 2.5" tail pipes will definitely help in the noise department. Next question is the cross over. Again, a personal choice. I prefer the standard "H" design over the "X". The "H" gives the car a more traditional muscle car sound as compared to the "X" design, which tends to give the car a more raspy sound.

66rat, I have heard good things about Borla and they are definitely a possibility. Years ago the 68 Charger I restored ( mid 1980’s) had an H pipe. I did not mind it then but it seems so many use an X pipe now. Was not sure if it was better technology. Thanks,

Joe

 

[71malibuu]

For what it’s worth 650hp 496.
2” header primary
3” collector
3” pypes race pro kit.
3 x pipe
First dumped at rear axle, I think that any exhaust sounds terrible on the street. Acoustics are miserable. Then Extended them out the rear at the factory location….. excellent. No drone no reverb. No difference in et.

 

[hydro462]

X pipes turn a dual exhaust system into a single exhaust.

 

[Kopfjaeger]

Hydro,
Thanks for posting. I can wrap my head around that. Our vehicles had no cross over from the factory, while Chrysler performance vehicles had the H pipe. Gimmick or did it add an advantage?

I guess I did not really put too much thought into the exhaust system. Sure I’ve looked at pictures, and listened to sound clips. I just assumed that what I saw in most exhaust systems was the best route. I know better than that, or at least I should. I‘m not looking for a specific exhaust note but I certainly don’t want a lackluster exhaust sound, after all the work and $ I’ve put in to her, so far. I’m not opposed to two pipes with no attachment nor am I opposed to having them connected.

I guess I want an efficient system that isn’t overly obnoxious, emphasizes my engine construction choices, enhances its performance, and does not camouflage or water down the fact that a BBC lives under the hood and powers her.

I plan on visiting a local custom exhaust shop that claims to specialize in muscle car/race exhaust systems. I just want to go in with a bit of knowledge and not be steered to whatever is popular at the moment.

Muffler selection is confusing me. I hear great things about Borla but there seem to be several selections there.

I would be greatfull to every and all suggestions so I can research and make an informed decision.

Thanks in advance.

Joe

 

[Lew540]

I run the Borla XR1 good muffler straight through design and stainless.

 

[shovelrick]

Hydro,
Thanks for posting. I can wrap my head around that. Our vehicles had no cross over from the factory, while Chrysler performance vehicles had the H pipe. Gimmick or did it add an advantage?

I guess I did not really put too much thought into the exhaust system. Sure I’ve looked at pictures, and listened to sound clips. I just assumed that what I saw in most exhaust systems was the best route. I know better than that, or at least I should. I‘m not looking for a specific exhaust note but I certainly don’t want a lackluster exhaust sound, after all the work and $ I’ve put in to her, so far. I’m not opposed to two pipes with no attachment nor am I opposed to having them connected.

I guess I want an efficient system that isn’t overly obnoxious, emphasizes my engine construction choices, enhances its performance, and does not camouflage or water down the fact that a BBC lives under the hood and powers her.

I plan on visiting a local custom exhaust shop that claims to specialize in muscle car/race exhaust systems. I just want to go in with a bit of knowledge and not be steered to whatever is popular at the moment.

Muffler selection is confusing me. I hear great things about Borla but there seem to be several selections there.

I would be greatfull to every and all suggestions so I can research and make an informed decision.

Thanks in advance.

Joe

If you want go to Youtube and look up Shovelrick1, I posted the sound of my full 3" Pypes X system with Violator straight through mufflers on both my 8.9-9:1 comp 454 and 10.8:1 489, H pipe will sound deeper or more muscle car sounding and my 64 T-bird with a 390 had a factory H pipe

 

[Kopfjaeger]

Ok, visited a somewhat local garage that does custom exhaust systems. It was a good sign that I was at the right place, as there was a C2 Vette, a Cougar, and a 70 Chevelle in the lot.
The place is owned by an old school street racer and he and his son run the place and wrench. After talking to them about what I was looking for, they suggested a complete parts kit, in order to keep the price down. The son suggested Magnaflo mufflers but was open to anything that I wanted. His suggestion was to listen to sound clips, which is tough due to the numerous different factors involved. Regardless, he said he may have to tweak the pipes to get it to fit since many don’t fit well, right out of the box.

The issue I’m seeing with pre fab kits is, they are either 3” or 2.5” front to back. There is no ala carte type selection. I can find a 3” stainless system with H pipe, then I’m getting 3 inch tail pipes. Most systems exit at the rear bumper, but a few exit in the stock location. Also the most mufflers seem to be center/ offset. I’m not sure if I need offset/offset. In the research I’ve done here, it appears I need offset exit for space and clearance. Regardless it looks like I’ll be getting a 3” muffler and reducing it to 2.5 at the exit.

So, any opinions on Magnaflo mufflers? Any ideas on where to get just 2.5“ mandrel bent turn down tail pipes that exit at the factory location, in stainless? Or is custom bent where I’m heading? Buying both a 3” and a 2.5 system just does not make a lot of sense. I had Dan Lemon put V band ends on my headers so doing the same at the front or rear of the muffler makes sense, in case I need to drop the system for trans or clutch work. Kinda feels like I’m heading toward custom system, huh?

Thoughts and suggestions, very much appreciated.

Joe

 

[70GS455]

Here are a la carte pieces where you can mix and match 2.5", 3" etc

Sent from my SM-S901U using Tapatalk

 

[70GS455]

Exhaust | TAPerformance.com

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[mrpaticular]

Xcelerator muffler, great deep tone and straight through. Install reversed.