75 Headers????

[clar2001]

Is any one running headers on a 75 with 400auto tranny.
I would like to run duels but don't think I can,becouse of the tranny.
Will settle for headers and single back to duels ...

What kind of headers ???????????????????

 

[Classicvette63]

On the '75 I had years ago, I ran headers with the 400 auto. I had Blackjack AK5000 headers with 3" dual pipes running straight back to a pair of "turbo" type mufflers. Awesome setup. Don't think the make the Blackjack headers anymore. Too bad because afters 3 years of sitting outside there wasn't one speck of rust on them. Figures, something finally works great and they discontinue it. Classic

 

[MaineShark]

Is any one running headers on a 75 with 400auto tranny.
I would like to run duels but don't think I can,becouse of the tranny.
Will settle for headers and single back to duels ...

What kind of headers ???????????????????

Why would the tranny prevent you from having dual exhaust pipes?

Anyway, I seem to recall that the Hooker SuperComp headers are supposed to fit very well. Maybe try doing a seach with that name, and seeing what others say.

Joe

 

[clar2001]

I will check out the Hooker headers ,I thought the linkage on the drivers side tranny would interfear with running duels ??? guess it will work.

 

[MaineShark]

I don't see why it would. All C3's had dual exhausts, up through '74. The only thing that's different, mechanically, for '75 is that the hanger in the unused crossmember cutout is missing. Replace that with either a stock or universal hanger, and you're golden.

Clearance with the tranny linkage is close, but there is clearance.

Joe

 

[clar2001]

Ok I just crawled under the car the linkage is right in front of the hole takes up all that space no way any size pipe will fit there ,to bad I found some really sweet headers you recommended Joe.
I like side pipes but there illegal in Ca.
hate to use headers and half to run a single pipe.

 

[MaineShark]

Gotta be something funky going on. That hole was used in '74 for an exhaust pipe, and there is no difference between the '74 and '75 crossmembers, except for the missing hanger. The hole location is identical.

Anyone else want to hop in on this one and explain why there is a clearance problem?

Joe

 

[clar2001]

I'll take a pic and see if I can post it this weekend it's hard for me to shoot small pics.

 

[r1_addict]

Go to this link, look at the corvette application footnotes. Footnote 22 states that the 1 5/8 hooker headers will not fit Turbo 400 applications. I would like to get the ceramic coated set I am sure I have the TH350 that came with the base L48 but have to verify...

http://www.holley.com/HiOctn/ProdLine/Products/ES/ESHHCH/Comp.html#Footnotes

 

[clar2001]

great foot note thats the fact ,I'm looking now at shorty headers running with stock pipes and flowmaster 40s
The shorty headers look about the same size as the manifold but I haven't goten exact measurements yeat.......

 

[r1_addict]

Let me know about the shorties. I would love to mate some headrs to my 73!

Bill

 

[elseyj]

Bill,
The Hedman #68300 bolted right into my 73.
Jim

 

[clar2001]

Ok here is what I'm looking at super competition headers Block Huggers here is the url


http://www.holley.com/HiOctn/ProdLine/Products/ES/ESHHSCH/BlockHug.html

run these with stock 2 1/2"pipes single to duels and flowmaster 40s

Good combo ? can't run duels half to do sothing .

 

[r1_addict]

Just a quick note. My guy at the locak speed shop tells me the Hoocker header will bolt right in with no issues. He has done quite a few, so the answer is clear!!


Bill

 

[clar2001]

Yes the headers will bolt on, but I cannot hook up pipes,thats why I am looking at Hooker block hugger headers ,I have a 400 turbo trans so I can not run duels.

 

[MaineShark]

Okay, your car is mechanically identical to a '74, as far as this stuff goes. There is a missing exhaust hanger, but the tranny and crossmember are in the same places. '74 had true dual pipes, so your '75 can, as well. If the Hooker headers won't fit, it's because the collector is too large, or in the wrong location, or somesuch. Check with some other header manufacturers, because it is an absolute certainty that true dual exhausts will fit your car. All you need to do is find headers that will work correctly.

The TH400 was used in C3's all the way through '77, so that transmission is not the issue. Interference between those particular headers and either the transmission or the crossmember, is the issue. Other headers will work.

Joe

 

[clar2001]

Like I said before the headers and collectors will fit,the crossmember hole on the drivers side is comptely blocked by the linkage.
So the exaust pipe can not run that way.
Hooker even states they will not work on this car as posted in a eariler thread with link.
Maby this car had a 350 tranny stock & that was changed to a 400,so now the crossmember doesen't work with duels I don't know....

 

[MaineShark]

You may want to check on that crossmember. If it doesn't have clearance, then something is seriously wrong. You might want to start a thread in the Tech Forum to see if you can get some pitures of a correct crossmember, because dual exhausts should fit perfectly.

Joe

 

[r1_addict]

I have seen crossmembers that have been changed in the past! I guess unless you know the tru history?

Bill

 

[Vettart]

I used the Mid Am 'Off Road' exhaust kit, Dynamax mufflers and Dynamax ceramic coated headers. Fell ino place like factory. I had the fab a spacer on the A/C pump mount. No biggie.