Hello I have a stock 87 formula 350 with a l98 350 tpi and I'm planning on in the near future putting headers and exhaust system and was wondering if a 3in system was too big. I plan on using a flowmaster or magnaflow system that follows the factory route and configuration I just wanted to know if it would have enough back pressure or not. Thanks

 

Not at all 3 inches is perfect for a stock 350

 

Is there anyway I can find out which ones are ok. I was on summit and a flowmaster system came up and it says it's all good but I don't want to buy a whole exhaust system only to find out it's actually not helping my car.

 

Are you doing this for sound or actual performance? If your going for all out performance/flow then I would recommend a single in/out muffler. The crossflow design is not the best when it comes to flow. With that said, a stock l98 will do just fine with one of the better crossflow mufflers. Ie, hooker, magnaflow, corsa, borla. Notice I didn't mention flowmaster.

 

Some longtubes, a mufflex y pipe and one of their 3.5" systems will allow you to grow into the system. It will be a little overkill for a stock l98 but you won't have to buy another system if you decide to mod the motor.

 

Yah, what sheikss said. I paid several hundred for a 3" for my lightly modded 350 but then when I put my 406 in it was really holding me back so I spent another several 100 for the 4 inch.

My point is, what are your future plans? Beyond just headers and exhaust as you listed. If no other plans, then yes my opinion is 3" single in/out would be best. My experience is MagnaFlow over Flowmaster

 

Manual or Auto Trans? That will tell if you if you can run longtubes or not. If you don't have a custom trans crossmember, you can't fit long-tubes under a car with an auto.

Dyno Don or Hooker 2055's (both come with Y-pipe), then your 3" catback of choice. Flowmasters are liked here on the boards here for the sound, but are one of the worst flowing mufflers.

I personally ran a Hooker Aerochamber muffler which I loved, and now a Magnaflow 3" catback because the Aerochamber rusted out.

 

I've got Auto, have hooker long tube headers, mufflex two 3" pipes into single 4" y-pipe. Factory cross member only needed little modification. But I also don't have cats and I'm not using factory routing.

 

Auto car here with factory crossmember, hooker longtubes, mufflex y pipe and a hawks 4" sinister system with a dynomax muffler.

 

Keep it simple for him guys. Dyno Don headers will be good enough for him with a 3in cat-back system. Magnaflow is the best system to use on his car.

 

All 350 cars came with a factory 3" exhaust - just that is is not mandrel tubing like the aftermarket's offerings. So don't hesitate for a second to put a 3" on your car.

I have a Magnaflow system on my GTA (also their y-pipe and cat) and the bang for the buck is off the charts - its 409 stainless and has beautiful polished tips. Now I also sell their systems through my company and have not had a complaint about fit, quality, or warranty - some people don't prefer the sound, but there are other options.

 

Mine was 2.75 lol. Walker still sells replacement i pipes for under 60$ i believe it is. Cheap upgrade for those 2.25" factory 305 guys

 

That is opinion.

 

3" intermediaries around auto - it takes effort to fit.

 

Basic system out the box. Unless you want a bunch of noise.

 

There's noise, then there's music to the ears - all in the ear of the beholder, I guess.

 

If that is the Walker pipe that necks down to 2.5" as it enteres the muffler - steer clear! Had one on the GTA when I bought it... Magnaflow fixed that right up.

 

TRUTH!

I personally don't like Flowmasters. I prefer quieter at idle and cruise. IMO, Aerochamber is the best combination though the Magnaflow I replaced my rusted out Aerochamber with is really growing on me.

 

I agree, the cars I've heard with the Hooker Aerochamber sound great.
Heres the cat back with the muffler = http://www.jegs.com/i/Hooker-Headers/520/16823/10002/-1
Heres a video =

 

Those headers are awfully expensive for mild steel.

If he was going to go with steel headers, I'd go with Hedman. Like a third the cost.

Otherwise, I'd go with stainless. Which are still cheaper.

-- Joe

 

Anybody use the Jegs?

 

The what??

-- Joe

 

By all means, buy the cheap crap first, there is always time to go back and spend your hard earned money again when you figure out your mistake.

 

What's the difference between your cheap crap and Hedman's cheap crap? Both are made/welded in California. The only difference I see other than the price is that Hedman makes their own bends and you buy yours.


^^ Hedman factory

Again, if the OP wants non 'cheap crap' he should get stainless headers.

-- Joe

 

I wouldn't call hedman or hooker headers a mistake or cheap crap. They are very good entry level or daily use headers.

Heck I have 2 sets that are old... Still in use.

A set of hooker shorties that I bought in 1998. They have been on 3 cars and like 5 engines. Been on my dad's daily driver for the past 6 years.

A set of hedman long tubes that my dad bought in 2004. Used on 2 cars, 4 engines and has been on my car for the past 6 years (we swapped headers 6 years ago)

 

I would, in the industry, 5/16th head flanges that leak and 1/4" collector flanges
that warp when you tighten them is considered "cheap crap" and ports that don't match the heads is poor quality.

If you can't tell the difference ...oh well.

 

Heh. You California guys are pretty funny.


-- Joe

 

Just a difference of opinion I guess.. No leaks, no wrapping here and I didn't have to sell a kidney to buy them.

I know you make and sell headers and from what I have seen yours are very nice, top notch stuff, no question to that, but I don't have the funds to buy a set of steel headers that's 4 times the price of off the shelf ones.

Trust me I get what your saying and I do somewhat agree, but like I said since 1998, no rust holes, no leaks, no bent flanges.. I use stock fel pro exhaust manifold gaskets, and dead soft copper collector gaskets. I paid $98 for the hooker shorties back then.

I think my dad paid $119 for the hedman long tubes when he ordered them.

As far as ports matching.. That's a 30 min job for me most of the times.

NO massed produced header is going to match every sbc head exhaust port. I have not looked into yours a whole lot but, I find it hard to believe that yours will be port matched to any/every head I pick to run

 

The hedman 68470 is the best bang for the buck. They use 1/4" header flanges and 3" ball/socket collectors. They don't leak, they don't hit various places in the engine bay. I've run these on 355" motors trapping 120mph in the 1/4.

Again, for a 'step up', go with stainless headers.

You can also get 1 3/4" shorty headers, stainless - tig welded, on ebay with 1/2" thick flanges for under $200 but you will have to make a y-pipe. They don't advertise for fbody but they fit the engine bay/steering shaft.


When I first saw the Dyno Don headers I had assumed the huge price tag was due to having a CARB EO number (i.e, 50 state legal). That's something that I could justify, since going through the testing is rather expensive and you need to have a return on your investment.

I later found out that his son was telling people to lie to inspection stations telling them they were "SLP headers" and to use SLP's carb EO number:

https://www.thirdgen.org/forums/exha...ml#post3564937

https://www.thirdgen.org/forums/exha...ml#post3566897

I'm kinda surprised nobody is in jail yet.

-- Joe

 

For a car up to X power, a 1 3/4 shorty (like Dyno Dons) will be just fine along with a 3" stainless catback that has a strait through design (with stock looking tailpipes for me)

 

Yes you can. I've got long tubes, a 700R and a stock cross member, the ONLY reason I scrape the exhaust is because my ride height is so low.