Headers and Pipes w/TH400??
Thread Starter
Instructor
Joined: May 2008
Posts: 154
Likes: 3
From: Indiana
Headers and Pipes w/TH400??
I have a 68, 327 and TH400 trans. Currently have the stock exhaust and ram horn manifold. I have been lookling for a decent set of small tube headers and exhaust system I can install. (2.5" or 3") Problem seems to be that the "do it yourself" exhaust systems have a note that indicates it doesn't work with a TH400.
I am not racing but would like to get a few more HP and good sound.
Any suggestions?
I am not racing but would like to get a few more HP and good sound.
Any suggestions?
Instructor
Joined: Dec 2007
Posts: 245
Likes: 2
From: Jersey shore NJ
I also used the corvette central system with a set of Hedman headers, I had the muffler shop bend me two peices about 1 1/2 feet long to go from the headers to the mid pipe. I also had a TH 400.
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
I am using the Corvette Central system also, with Hooker Comp headers. I installed the system back when I was running a 327/turbo 400 combo, and had to have a muffler shop finish the section around the trans. Cost me $90 at the time. Good thing is when I installed the 383/200R4 there were no issues with the "customized" exhaust section-everything fit fine
Thread Starter
Instructor
Joined: May 2008
Posts: 154
Likes: 3
From: Indiana
Advanced
Joined: Apr 2009
Posts: 96
Likes: 0
From: Columbus GA
George, that is NOT noise.....open headers can only be compared to MUSIC...But, not everyone appreciates good music!!!!
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
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Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
I have been rec. Dynomax Cerma Coat headers & many have them now.
You want flow not turbulance.
Some ex. pipe size guidelines:
Racing Head Service..... Dynomax
DUALS
2" .... 200 BHP...............100-200
2.25" 320 BHP................250
2.5 .. 400 BHP................300-400
3.0 .. 600 BHP................450-500
You want flow not turbulance.
Some ex. pipe size guidelines:
Racing Head Service..... Dynomax
DUALS
2" .... 200 BHP...............100-200
2.25" 320 BHP................250
2.5 .. 400 BHP................300-400
3.0 .. 600 BHP................450-500
Pro
Joined: Mar 2009
Posts: 703
Likes: 2
You will have to have a local muffler shop bend at least the first few feet from the header to the cross members holes (no other way around it).. There-after you can find exhaust kits and do the rest yourself or just have the muffler shop finsih the job since your alreay there.. Basically from the headers, the muffler shop has to bend the tube away from the trans to clear the 400TH shifter linkage and then back in again to hit the crossmember holes.. If you plan on using a chamber exhaust system you could buy the 3" diameter chamber mufflers and then buy the short tubes from Summit (pictured below) and that will at least get you to the muffler shop without running open headers. Keep in mind, they will sit very close to the ground because they will go under the cross member...
