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65 fastback exhaust sizing Posted by RICK on 10/6/2009, 9:54 am 71.244.226.163 What size pipe should I use with a 302/347 stroker, long tube headers, engine dyno at 440 hp and 440 torque? I am looking at the magnaflow exhaust system kit in stainless. It comes in 2.5" and 3.0". Your thoughts? How much sound difference between 2.5" and 3.0"?  Post an Intelligent Response

I use the 2.5, very good kit. Posted by Tubo on 10/6/2009, 11:46 am, in reply to "65 fastback exhaust sizing" 129.61.46.60 Local shop charged me $60 to install. Sound is...ah... Not LOUD, though it is somtimes Loud. I dont know about the 3.0, the 2.5 is already purdy tight fit around the gas tank(drivers side)and through the valance. Corky As Carrol Shelby(shoudda) said in 1963, "If ya want a RED car, go buy a Ferrari!!"  Post an Intelligent Response

Re: I use the 2.5, very good kit. Posted by 6sally6 on 10/6/2009, 1:03 pm, in reply to "I use the 2.5, very good kit." 68.58.231.240 Me too. I doubt there would be any NOTICABLE increase in power or sound going with the 3".2.5" seems to fit better. 6sal6 If it "crackles" like a Pro Mod..thats ALMOST enough cam!!  Post an Intelligent Response

2.5 is about max to clear the rear axle Posted by MustangSteve on 10/6/2009, 8:59 pm, in reply to "65 fastback exhaust sizing" Mustang owner since 1974 3.0" is like open headers ... I don't see how it could possibly get over the rear axle unless the car was all jacked up... Am open to learning experience on this one if someone has a picture... I used 2.5" headers to mufflers, then 2.25 out the back. As the gases move along the pipe, they do cool off somewhat, and take up less volume. Main thing is to get a mandrel bent pipe over the axle and not an exhaust shop hack job (like mine) MustangSteve http://www.mustangsteve.com http://www.mustangsteve.com/My66FB_Signature_marks.jpg  Post an Intelligent Response

....3" pipe is sweet sounding,but...... Posted by jerseyjoe on 10/7/2009, 7:24 am, in reply to "Re: I use the 2.5, very good kit." 67.82.241.187 Stick with 2 1/2 SS.......jj  Post an Intelligent Response

Re: I use the 2.5, very good kit. Posted by RICK on 10/7/2009, 11:04 am, in reply to "I use the 2.5, very good kit." 71.244.226.163 When you say it is "not loud" though "sometimes loud" what do you mean?  Post an Intelligent Response

Re: 2.5 is about max to clear the rear axle Posted by Ted on 10/7/2009, 11:50 am, in reply to "2.5 is about max to clear the rear axle" 71.17.155.236 Hey Rick I have 2.5 exhaust on my 65 coupe and I get a rattle where my pipes are so close to the shackles and through the rear valance. I only have about 1/4 inch clearence going past the tank area. But who cares it sounds great. I have the same SS mufflers and SS pipes as you are talking about and the sound is sooooooo sweeeeeeet...Ted from Canada  Post an Intelligent Response

It's not as loud as Flowmaster 40's at any time. Posted by Tubo on 10/7/2009, 12:39 pm, in reply to "Re: I use the 2.5, very good kit." 70.191.197.45 Get on it and the volume increases. I have noted a "drone" at highway cruise 66-78 mph. Though only when all the clamps on the system are super tight. Back off on the clamp torque and let the system "relax" a little, NO Drone. Corky As Carrol Shelby(shoudda) said in 1963, "If ya want a RED car, go buy a Ferrari!!"  Post an Intelligent Response

Go 3" in and 2.5" out... Posted by Mach1_Ron on 10/7/2009, 12:57 pm, in reply to "2.5 is about max to clear the rear axle" 206.196.241.19 They make mufflers that have this arrangement. The OLDER I get, the FASTER I was.....  Post an Intelligent Response

Good deal still available?? Posted by Tubo on 10/7/2009, 1:08 pm, in reply to "65 fastback exhaust sizing" 70.191.197.45 CALL Performance Peddler ask for the Forum Internet price, I paid $348 delivered 3 years ago, simular pricing still available. Corky As Carrol Shelby(shoudda) said in 1963, "If ya want a RED car, go buy a Ferrari!!"  Post an Intelligent Response

Hey Corky Posted by Ted on 10/7/2009, 5:33 pm, in reply to "Good deal still available??" 71.17.155.236 Hey Corky......I have been seeing alot of those X pieces on exhaust these days, is it any better than a pipe going across to each other like an H pipe?? What is the advantage of it, does it sound better or what??Just when figure I got a handle on things new stuff comes out and I want to change.....Ted  Post an Intelligent Response

Re: 65 fastback exhaust sizing Posted by Mark R on 10/20/2009, 12:09 am, in reply to "65 fastback exhaust sizing" 24.178.238.41 65 coupe 408W Hooker ceramic super Comps w/ceramic coating 1-3/4" long tubes to 3" pipes - X pipe - 3" I/O Magna Flows and best I could do was 2.5" tail pipes all mandrel bent - no rattles good fit, flanged at header - X pipe - muffler I&O , so tail pipe removal is easy !  Post an Intelligent Response

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REMEMBER!!! When posting a question about your Mustang or other Ford on this FORD MUSTANG FORUM, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.