dirt4me

I have a 1970 cutlass supreme with a 350 motor and single stock exhaust. I want to uprage it to a dual exhaust. And need some help. I have been looking into it and at first was thinking flowmaster but many people dont recomend them. So I was thinking magnaflow. Any recomendations on this exhaust. Also I dont know to much about exhaust but will I need downpipes or what all do I need to do this. Thanks for any help.

oldcutlass

If you want to do it inexpensively, take it to a reputable exhaust shop that does custom exhaust systems. Not a franchised shop like a Midas, etc. Talk to some of the local folks in your area for recommendations. I'd go with 2 1/4 or 2 1/2 all the way through the tail pipes. I'd also go to some car shows and listen to other exhaust systems and find the ones you like with similar engines with what ever performance mods you have or want to have on your car, then duplicate the mufflers. I have an exhaust guy in town who is a true artist.


If your going to do it yourself you'll need to cap the crossover, you can buy or fabricate one. Pypes sells kits.

rcrac3r

I will be doing the same thing to my 72'. I will be installing headers & going with Magnaflow mufflers & 2 1/2" pipe to the back. Depending on what you want to do, you can get a muffler shop to run pipe from your manifolds if you don't want to go with headers. In this case you will need the crossover port on the right manifold capped, this you can find from Ebay or other sources. The actual muffler you go with tends be a personal preference. I've heard from some folks the Flowmaster mufflers will have a drone to them when cruising on the highway. I've heard a few cars with Magnaflows & they sound really good.

dirt4me

Thanks guys I dont want to spend more than like 600 it but I wa t it done right so if it goes over. Well I think im going to go with magnaflow exhaust 2.5 and ill have to figure out if I can do it on my own my neighbor did his own so he will help me out but I will have to figure out what all I need and try it someday soon. Anymore recomendations out their would be greatly be appreciated. Thanks

Cutty1972

Had a local exhaust shop do true duals straight off the manifolds with 18" glass packs. 350 4bbl often gets mistaken for a big block.

Mr Nick

You should be able to get 2 1/4" prebent tail pipes very easily, then just have from the manifolds to mufflers bent. They aren't mandrel bent, but with a mild 350 you'll never notice a difference. That's what I did on my 70 convt, (stock engine) with Hooker Aerochamber mufflers, sounded very nice.

kitfoxdave

I used the pypes 2-1/2" system with dynomax ultraflo mufflers. (Stainless) bolted right up no muss no fuss....

76olds

but with a mild 350 you'll never notice a difference. with Hooker Aerochamber mufflers


His neighbors will lol . They wife will hear you coming home late for sure

coppercutlass

I believe pipes sells a down pipe kit. Or you can get creative and buy and modify a set of flanged pipes to fit the manifolds and make your own with prebent sections from the local AutoZone. Then once you get that figured out buy an x pipe kit for 75 bucks from summit and some thrush welded mufflers. Similar in sound to flowmasters and less than half the price. So for under 150 you will have an x pipe kit to the rear axle. Tail pipes are over rated. Turn downs look so much cooler . This is the only good pic of my exhaust I have its sitting against the wall there. I run headers and hooker aero chambers 2.5 in. pipes. You can use 2 2in. flanged pipes to come down from the manifold then you can cut them short and use a 2 in. to 2.25 or 2.50 in. reducer in reverse to go from 2 in to 2.25 or 2.5 to upsize. Once you get headers its much easier to do this stuff lol. Now I know on the manifolds you have one bigger down pipe on the driver side I think my memory is fuzzy . Then behind it will the a 2 in. hole for the cross over. On my dads car I capped the 2 in. crossover hole and used the big pipe and I upsized the side with the lone 2 in. outlet.

442craig

I just bought the Pypes 2 1/2 system with street pro mufflers for my 68 442. The kit with down pipes was $566 from OPGI delivered! I am going to install them in my garage this weekend. I'll let you know how easy it was. I was thinking of Magnaflows too but wanted a little more of a classic muscle car sound.

Craig

dirt4me

Ya craig that would be great that was the other exhaust system I was actually looking into. Let me know how it sounds and how it is easy or hard it was to install. Thanks

dirt4me

These were the two exhaust system I was considering any opionons on these?

Magnaflow 2.5 perfermonce exhaust
http://www.autopartswarehouse.com/sk...ings+Clearance

Or

Pypes performance 2.5 crossmember back with violator muffler
http://pypesexhaust.com/i-12200865-6...tem-sga10.html

70olds455

I got the pypes exhaust system with street pro mufflers for my 71 cutlass and I like it. They sell downpipes if you don't want to put headers on your car. I think the street pro mufflers are louder at idle than the other mufflers they offer. Definitely a big difference sound wise over stock single exhaust.

jag1886

As far as mufflers I recommend DynoMax super hemi turbos unless you like to be driven nuts by droning. I've used Flowmaster they are terrible and the Magnaflows are better but will still drive you insane after in 50 miles. As far as exhaust the system I always go to a local shop and have it done, it's nice to have a custom system with a guaranty.

442craig

I was looking a Dynomax too. The have a "VT" muffler that has a valve in it to fix the drone problem. Don't know anyone who has used them but sounded interesting!

Mr Nick

I had them on two cars, my 2006 GTO and the Cutlass. Took them off after just a few days both times.

kitfoxdave

Just a heads up, I was planning on the Dynomax VT, but I spoke to tech support on summit, and they had several returns on them because of rattling noise from the valve... they recommended Dynomax utraflo muffler instead.... (yeah, I went stainless to go with everything else under the car....)


The Pypes system down pipes fit fairly well. I used Thornton 350 JR manifolds and everything bolted up great, clearance to the lower front control are rear knuckle is really close... That may need a little massage... with a BFH.

dirt4me

I think I am going to go to a muffler shop after all to get a custom exhaust system just need to decicde on which mufflers now. Thanks for all your guys input much needed.

z11375ss

Flowmaster 40s. Watch the vid in my sig and you can hear what they sound like.

coppercutlass

If we are sharing exhaust clips I may aswell add mine lol. I personally love the aero chambers. There might not be much to my exhaust but It sounds awesome and performs. I also recommend an x pipe it helps more than an h pipe. click on the title if it does not pop up.

Alex72cutty

I like the sound of flowmaster 40

Alex72cutty

Love the sound. Good looking car too.. I bet Tobin had fun

z11375ss

Thanks for the props. Tobin is no more. Miss him like crazy. Especially now that it's warm.

coppercutlass

Sorry to hear about your pooch . Not to get off topic but we rescued my border collie / aussie mix from right way rescue. They take in dogs and pregnant dogs at risk of being put down then the pups get put up for adoption and eventually the mom does too.

z11375ss

That's a nice thing.

Alex72cutty

Sorry to hear about Tobin.

real57vetteguy

I recently installed the Magnaflow 2-1/2 kit on my 65 442 with edelbrock heads etc. I had run the Magnaflow set up on several different Ford cars I have had in the past and been VERY happy. Once the kit was installed on the Olds I absolutely hated the sound, it sounded like a cross between a Japanese motorcycle and a diesel truck, it was awful. Once I mentioned it in a thread and had several others comment that they had experienced the same thing with the Magnaflow kit on an Olds engine. I did slip the Magnaflow mufflers off and clamped up a long case Spintech muffler and it sounded GREAT.
I would seriously consider looking up Ram Air Restorations and taking a look at what they have to offer, they are very knowledgeable about Oldsmobile and they offer kits that have Spintech's included as well as other mufflers.
I like the Flowmaster sound and have run about 10 sets in my lifetime but as I get older I cannot handle the drone sound inside the car.

joe_padavano

I installed a Magnaflow on my 62 since it was smaller than the equivalent Dynomax. Note that the 62 F-85 has the muffler crossways behind the rear axle, so I used a third-gen Camaro muffler (single 2.5" in, dual 2.5" out). I also disliked the sound originally (it sounded downright agricultural in the midrange), but the more I drove the car, the more mellow it got. I can only assume that the fiberglass packing has become carboned-up, causing it to absorb more sound. By the way, the car sounds just awesome at W.O.T. at about 3500 RPM.

My Vista has a pair of 2.25" Magnaflows installed by a P.O. that are actually too quiet.

ELY442

I have the same car like yours but in a convertible. I did the dual exhaust by buying Thornton's exhaust manifolds that you can use 2 1/4" pipes. I bought my head pipes and tailpipes from Motorcity Supercars/Inline Tube. The mufflers are Dynomax Super Turbos. Fits like a glove and sounds awesome.

z11375ss

Thanks.