The Camaro/IA project I used their 3.5X system with 3" Ultraflows and mandrel Torque Tech 3" tailpipes I had(Torque Tech are aluminized and great fit but the guy retired about 2 years ago. He was out of A body even them and I got 2 of the last F body sets.

I had a muffler shop install the system and he did a great job tucking up even the 3.5 head pipes and X. Only issue we had was the header to X were way too short and the X to tailpipes were too long so more cutting and welding but it is as low as a 3.5 system can get. He spent time to do it and I paid for time $600. But it looks great.

A GOOD muffler shop can do wonders. Get the 3" system and if need be some mandrel SS bends for a muffler shop to use to cut and section to tuck it up. B man had some pictures of a nice mandrel system he custom made on one of his 64s.

If you want a box kit then this might work, https://www.magnaflow.com/products/1...s?aces=5883676 I used the 2.5" kit on my 65 with o/s ram air manifolds and head pipes fitment was good and I did it laying on my back in the garage with hand tools.

I have an EXCELLENT exhaust shop here in town. I will probably buy the Pypes or the flowmaster kit and have him install it. My main concern was whether between the two kits one was a better fit. I initially said I was going to install it myself but I want everything tucked up as nicely as possible and if something arises they have the tools to do it. I never said money is no object by the way and I am always bargain shopping. Also my next conundrum is a 3 inch muffler that won’t drone. Anyone got any feedback on that?

Dynomax. Favorite muffler, good sound quality and yet I've never had a set drone on any style exhaust system I've used here.

RJ's Custom piping is one of the few muffler shops in The United States, and the only muffler shop in the state with a mandrel bender.

RJ's Custom Piping

3813 Capital Blvd #104

Raleigh, NC 27604


http://rjscustompiping.com/mandrel-bending.html

The type of exhaust system might make a difference. And the amount of cubic inches and horsepower.

454 CID 604 hp 540 tq here......

"Mine was over a 50 hp increase as I picked up 4-5 mph in 1/4 mile but some of that was attributed from going to a non-mandrel 2.5 inch (probably squished to 2 1/4 or less in some areas over axle) to a 3 inch mandrel and being jetted correctly for the exhaust. It was a night an day difference after 4,500 rpm I could tell within 5 minutes of driving the car."

Keep in mind a mandrel bent pipe is a smooth pipe without any serrations, for a higher flowing system



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Exhaust Size Comparison: 2 1/4 Exhaust vs 3 Exhaust

https://www.hotrod.com/articles/ccrp...-inch-exhaust/


Engine Masters Ep. 9 Busts the Backpressure Myth: 3-inch vs. 2.5-inch Exhaust!

https://www.hotrod.com/articles/engi...-inch-exhaust/



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My brother just installed the high tuck 2.5" system in his '70 A body with 20" Super Turbos and the system is very impressive. Starts with 2" Doug's headers and has excellent ground clearance. His only gripe is he thinks it's too quiet, but he's used to the race car exhaust.

When did I ever say money is no object? I am doing all this on a disabled vets pension and my wife’s 1st grade teacher salary?

Buy the Pypes system, sell the mufflers that come with it, and buy the ones your want to use. That's what I do, on my 3rd system, about to install a 4th.

I loosely put the systems together, using the clamps, only tight enough so they don't fall apart for the trip up to a shop to have welded. The one shop I use do minor adjustments, as needed, and weld it up. They turn out great. (Except for the 71-72 valance exit systems, which the driver's side tip tilts slightly inward)

There are at least 2 shops in my area with mandrel benders, but they have to have a 'special guy' come in to use it, and he only stops at those 2 shops about twice a month. The one time I had him do one, years ago, it wasn't great, only 'good' at best. So instead of spending $900+, I take my chances with the Pypes setups and have someone weld them.

There's a new place close to my house that supposedly does premium, custom work, but haven't tried them. I will go up and check the shop out and talk to them, and may take a shot at having them weld up my upcoming system.

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You can buy the Pypes system without the mufflers also and use your own, I just did this.

I bought the flowmaster 2.5 inch mandrel bent system. It fit perfect.

Any feedback on the Borla mufflers? Willing to sacrifice some HP for good sound and NO drone

I have an issue with those 2 Hot Rod Mag tests. First test, it's with a 355ci, second test, no H or X pipe.

H and X pipes provide additional flow between exhaust cycles across the crossover pipe.

All know an X works better than an H, though sometimes it's not possible to 'fit' and X pipe due to clearance issues. Same with 3" tailpipes, sometimes you just can't fit them over the axle or past the tank.

Sometime when using OE looking tips, the larger 3" type repops just don't look right.

I bet if that second test had an X pipe, you would see less of a gain between a 2.5 and a 3" exhaust. But still agree there would be SOME difference. 10-15hp I think would be a max difference with a 600hp engine, and you do lose some TQ on the bottom end with larger pipes. So for roughly a 2% loss, I consider that nominal, and acceptable, in an event you don't want to run 3" tailpipes. When you have 600+, unless you are competing, 2.5 tailpipes are just fine.

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FWIW..When my car was running low 11's (11.3/121)the exhaust consisted of 3 inch x pipe 3 inch mufflers and 2.5 inch tailpipes. Just by removing the tailpipes the car picked up 1.5 mph and .15 in the QTR mile.

Yeah, in my particular case, I'm not willing to omit the tailpipes, and I want to run the 71-72 splitter tips. (A-body)

On the 'bird, I want to run the 2.5" hockey stick tips, and they look horrible in the 3" version.

For me, I can live with the performance hit.

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64speed, this is a have your cake and eat it too situation here. You want a 3" system, but you also want superb fit and finish and the most ground clearance you can get. Unfortunately, I don't believe that exists in a bolt-on aftermarket kit.

What you're wanting is going to require custom fabrication from a shop that can do it right, without a crush bender. The instant you start crush bending 3" pipe, you might as well have gone 2.5" to begin with.

That said, with the aftermarket bolt-on stuff, a lot of it is going to be in the install. Take your time, use floor jacks to position the pipes where you want/need them and be prepared to make necessary modifications. You can get even a 3" kit to fit decently if you're prepared for that.

I have a 2.5" with X Pypes system on my bird. I specifically went 2.5" because I didn't want to hassle with getting the larger pipe to fit and I absolutely wanted tail-pipes instead of dumps. The system fit fairly well, but it was still an install that required some cutting and several attempts at fitment to get things where they needed to be. You're correct that it is your money, but if Pypes doesn't make the product, they can't sell it to you. Instead, take that money, find a competent exhaust fabricator and have it created to your liking.

I put 3 inch tailpipes back on in the spring..the car sounded a touch rowdy! I have gone 126mph thru full 3 inch exhaust!

I used the the 3" Pypes system, X pipe, cutouts and 2.5" trumpet tips on a 66 GTO with 535 IAII. Went with the race pro mufflers. Love it so far, looks great sounds great and I have not noticed any drone yet. Not obnoxious at all