Good morning. TA-Performance sent the 3-1/2" into 2-1/2" reducers thinking I was running a 2-1/2" dual system. I paid a local muffler shop $20 to expand the ends from 2-1/2" to 3". I need to know if the size reduction (arrows) in my header reducers kill any power??? If so, I will order the 3-1/2" into 3" reducers from Summit.ou: Thanks again.
yes i would order a 3 1/2 that will mess with exhaust flow. You may want to call tourqe tech and get a 3inch xpipe it has a 3 1/2 inlet and goes to 3 inch on exit. basically half your system will be oversized and no flow restriction.
Take the reducers back to the pipe shop and have them cut off the reducer about 3" past where it first snakes down to 2.5". Have them expand it out to 3" OD. Make sure that the expansion goes all the way back to the funnel area. Then have them make you up (2)3" extensions to what you had. It may be cheaper for the reducers from Summit but you will need those extensions to fill in a gap.
Sorry, I don't have any extras around. I used my last setup on my '76 Century 455. Somebody mentioned this on another thread but if I was doing a "newer" Regal 455 now I would just use the standard V-6 complete alternator/AC compressor(smaller) bracket setup. Should bolt up with only minor adjustments. I know a guy from the Chicago area that runs that setup nicely and I ran the same setup years ago on a 350 Regal. Looks nice and factory for the year. I modified the factory '78 V6 setup(small compressor) to fit my '78 Regal 455 way, way back when but that never really fit great. That is why I went to the earlier large compressor on the TA. Also the later model Regal setup would have a hard time clearing the TA's hood.
... Just called Satellite Salvage; The guy said he has none now, but call back in a few days as he may get one or two in. At least I have a possible source.