Jegs has the long tube coated ones for my 1991 listed at $606 shipped. Having done a search over the thousands of posts on the subject, it appears that the Hooker headers are the best bet with regards to the emissions sensor. From what I read, the Hedman Elites require more than just a simple bolt on. If I am mistaken about that, please let me know...

By the way, whats the difference between these two headers?

http://www.jegs.com/i/Hooker/520/2149/10002/-1/744807

http://www.jegs.com/i/Hooker/520/2151-1/10002/-1/744807

They both say they are for 1991 Corvettes, but the second one also says they fit the LT1.

Anyone know of a group buy or a vendor with better prices? $606 seems cheap after modding my C5 and C6 so I probably shouldn't complain, but hey, if there is a deal to be had I'd like to know about it.

Also, the guy put Dynamax mufflers on the car and the drone is unbearable. Have any of you Hooker guys found a solution that keeps most of the noise outside the car and not in the cabin?

 

www.speeddemonmotorsports.com

I think the 2149s have the air/EGR pipes the 2151s do not.

 

already modding

 

Had the car on a lift today. Had you seen the pathetic weld job on the OEM header to the rest of the exhaust you would see that buying new headers is more of a "repair".

 

Thanks. Do I need to buy any thing else with the header to make it compatible with my 1991? When I did long tubes on my GTO I had to buy a longer wireing harness for the O2 sensor.

And why does Hooker have a Y pipe for a Corvette? For true dual exhaust, shouldn't it be an X pipe?

 

The hooker Y pipe when used with the headers, replaces the L98 front Y pipe with the two cats. This Y pipe hooks to the third center cat in the L98 exhaust.

 

I would buy them from Summit. I use TPiS myself. The major difference is the placement of the O2 sensor, but the amount of time it takes the two different headers to get into closed loop is not a big enough difference to notice the change in fuel mileage.

L98 cars do not have true dual exhaust, its a 2-1-2 system with a front and rear Y with a main cat bridge between them. The 16720 Ypipe replaces the stock front Y and allows you to just bolt the primaries to the main cat, so no custom work is required. There are some issues with fitment of the Hooker Y, however, and some people elect to go with custom Ys or choose to go true dual.

http://temp.corvetteforum.net/c4/vader86/headers.html

About resonance, its not going to be avoidable once you put headers on. Some brands of mufflers like Corsa are very good at reducing it though. Some tricks to try to reduce it are putting a bridge in the rear Y pipe (connect one side to the other after the split), exhaust extensions past the bumper, or plugging up one of the dual outlets on long trips. Otherwise, you have to deal. C4s have that big resonance chamber behind the driver, so theres no avoiding.

 

So, what would happen if you make a L98 dual exhaust, like the LT1 exhaust system?

 

If you deleted the main cat and went with new high flowing bullets, you will gain power. Its not really going to do anything else though, and its not a huge difference in power on a stock/near-stock engine.

 

Ah, that explains it. The guy before me turned it into a dual exhaust and there wasn't any factory Y pipe under the car.

 

Their web site does not process orders and the phone number goes to a different business. I think they are out of business. Any other recommendations?

 

What about Dynamatting teh cargo area? I've heard also that teh ceiling tiles used in office buildings cut to
fit our cargo bays, slipped under teh carpet help too. I've not tried this, only heard it somewhere....

 

Have ya tried Exoticmuscle.com yet?

 

www.ajusa.com

 

No problems with Hedman's on my 87, direct bolt up, just Y-pipe change out at exhaust shop.

 

Phil, if you dig around you may be able to find a set for $550 or so but thats it. Summit has them listed for $605 also. The 2151s do not come with the emmisions equipment (egr tubes). A true dual set up is the best way to go on the L98 cars and its a worthwhile mod. I used to have before/after dyno results on my 90 and it picked up quite a bit.
The resonance problem has been debated endlessly here. Corsa seems to have the least. My set up consistes of the hooker 2151s, true 3 inch duals, H pipe, no cats and flowmaster super 40s. Its not bad except at 1500-2000rpm where its very annoying. I dont DD it so I can put up with it.
Another popular option is to go with a modifed LT1/4 stock exhaust. The LT1/4 cars allready use a true dual setup and it can be modded to fit your headers. Just be sure to use the stock resonator. You may give up a bit of sound and HP (not more than 4 or 5) but it'd be quiet and cheap if you can find a takeoff.

 

Another popular option is to go with a modifed LT1/4 stock exhaust. The LT1/4 cars allready use a true dual setup and it can be modded to fit your headers. Just be sure to use the stock resonator. You may give up a bit of sound and HP (not more than 4 or 5) but it'd be quiet and cheap if you can find a takeoff.[/QUOTE]



I have an LT1 system on my '86 coupe with Lingenfelter 1 5/8" headers. Easy to fit up to the cat back LT1 system. I like the sound (kinda like quiet flowmasters) that results from using that system without the quieting effect of the cats. Make sure you get the stock LT1 hangers at the trans and the diff.