Jack, The HP increase is assuming the engine already had dual exhaust. I'm only talking about the difference between stock cast iron dual exhaust manifolds verses WZ cast iron dual exhaust manifolds (which are different from stock manifolds) verses tubular exhaust headers. I'm only changing one variable at a time.
Changing from stock single exhaust to dual exhaust using the same cast iron exhaust manifolds that came on the car is usually good for approximately 10-15 HP, depending upon the exhaust system components used. Many A-bodies came stock with customer ordered dual exhaust, along with B-body cars that had a dual exhaust option. Milton Schick 1964 442 Cutlass [EMAIL PROTECTED] ----- Original Message ----- From: "Jack Kopf" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, November 29, 2006 7:15 AM Subject: RE: 455 rebuild Headers / manifolds >I would expect to see more than a couple of ponies going from a stock to > duel exhaust. The olds design is pretty restrictive feeding the drivers > side > into the passenger side manifold, than forcing the gases to make a 270 > degree change in direction. > > JK > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Kerry Doyle > Sent: Wednesday, November 29, 2006 8:33 AM > To: [email protected] > Subject: Re: 455 rebuild Headers / manifolds > > Milton > thats a big jump in HP going to headers.Once I have > the 68 on the road and all is settled down and running > fine I will want to get it fitted for a good quality > coated set of headers and the full 3" pipes; > Kerry > > > --- "Infinite Space Systems, Inc." <[EMAIL PROTECTED]> > wrote: > >> Kerry, >> >> Yeah, that's cheap at $50.00. I sold a pair in less >> pitted condition and >> cleaned and painted for $350.00 some time ago. It's >> all in what you want. >> The W/Zs might give you 2-4 more HP. A good set of >> headers will give you >> 20-40 more HP. >> >> Milton Schick >> 1964 442 Cutlass >> [EMAIL PROTECTED] >> >> >> ----- Original Message ----- >> From: "Kerry Doyle" <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Tuesday, November 28, 2006 5:43 PM >> Subject: 455 rebuild Headers / manifolds >> >> >> >A couple days ago someone was debating over stock >> > maifolds or headers. >> > >> > Evil # 230057792398 >> > >> > is for a set of used W Z manifolds that might go >> > cheap?? >> > >> > >> > >> > >> > -- >> > No virus found in this incoming message. >> > Checked by AVG Free Edition. >> > Version: 7.5.430 / Virus Database: 268.14.19/556 - >> Release Date: >> > 11/28/2006 3:22 PM >> > >> > >> >> >> > > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.430 / Virus Database: 268.15.0/557 - Release Date: 11/29/2006 > 4:15 PM > >
