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73-87 Chevy _ GMC Trucks => Performance => Topic started by: sphnyx991 on January 06, 2011, 11:41:41 pm

Title: exhaust pipe size?
Post by: sphnyx991 on January 06, 2011, 11:41:41 pm

so i got a chevy zz4 350 motor in a my 1984 chevy k20 with a 6 inch lift with 35" tires, this is a new motor and i havnt fired it yet and i need to get some exhaust for it, i have mufflers for it already but i saw summit sells a header back exhaust system for it minus mufflers but it only comes in 2 1/4" piping, would this be suitible for my mild 350 or would running 2 1/2" piping be worth the extra work of fabbing up my own system. i have fabbed a couple systems in the past but like the idea of a bolt up system. any info would be appreciated, thanks

Title: Re: exhaust pipe size?
Post by: lechez71 on January 07, 2011, 01:21:02 am

go for 2 1/2" pipe or even 3" if its not going to be mandrel bent, IMO 2 1/4 is to small.

Title: Re: exhaust pipe size?
Post by: beastie_3 on January 07, 2011, 03:01:25 am

Go 2.5

Title: Re: exhaust pipe size?
Post by: screamin86 on January 07, 2011, 03:50:49 am

2.5 will be plenty I believe dual 2.5 will support somewhere in the 450hp+/- range with no problem anything over that is a overkill.

Title: Re: exhaust pipe size?
Post by: Jim Rockford on January 11, 2011, 07:54:46 am

2 1/2 vote here also, but if you went with a 3 inch single you would keep alot more torque. Also  have you changed the gears in your axles for those tires? That will make even a good motor feel like a dog .

Title: Re: exhaust pipe size?
Post by: screamin86 on January 11, 2011, 12:50:34 pm

I run a single 3in and couldn't be happier.

Title: Re: exhaust pipe size?
Post by: bake74 on January 14, 2011, 11:30:24 pm

     The above info is all good, duals = 2.5"  or single = 3"