I want to add headers to my 71 454 / 4 speed. I was considering either hooker super comps or headman. Any suggestions or things I should consider when purchasing? My car has air and power steering. I also have recently added a complete 2.5" exhaust system. How much work is involved in connecting to the new exhaust. Also, how much power increase should I expect to gain over the stock ram horns.

thanks in advance :cheers:

 

I have the headman Ceramic coated on my BB. Very pleased. Regardless of what make you get, get ceramic coating. NOTICABLY less underhood temps

Tip: When you put them on, remove clutch pivot arm (if manual tranny). Remove the two long engine mount bolts. Place a large (piece off wood on a jack under the oil pan (to keep from denting/damaging oil pan), jack engine up about 2" (It will go up with transmission still attached). Dont force the engine up after you feel it has gone up and stopped. This 2" will really ease installation. You dont want to scratch up your new babies.` Install passenger side from UNDERNEATH the car. Passenger side will have to go from the top, but its easy. You will also need to jack your car up on jackstands first

As far as HP gains, I couldnt really say how much as I havent dynoed anything, but you can feel a difference

 

Melvin,
How is the plug clearance with the Headmans?

 

Check out what Stahl has to offer, I have their sidemount headers on my BB and they were great fit and quality. :cheers:

 

Plug Clearence: depends what heads you are running. Im running GM perf heads. Number 1 is VERY close. Not sure of what clearence you would have on stock heads

 

I'm putting Hooker Supercomps on my '68 427. I got a good deal on a new set which was the deciding factor in my choice. I did a trial fit and found one of the tubes on the passenger side very close to the idler arm (probably about 1/8"). I did a little cutting and welding on the tube to gain clearance there. I could have just tapped it in with a hammer but I didn't want it to look Bubba'd. I just took them to get ceramic coated last week. I'd recommend getting them bare so you can do all the trial fitting and then send them out for coating. Had I bought them already coated, it would have been a waste because of the modification I had to do for clearance.

Maybe the Hedmann's will fit better if you go that way. They are definitely cheaper.

In connecting the exhaust, I bought a set of the Hedmann collectors with the Z pipe extensions from Summit Racing. They are the same price as regular collectors. I cut the extensions in half and added a 3" long piece of 2 1/2" diameter pipe welded between the two halves. This got the offset between the header collector and the stock exhaust at the cross member just right!
I then found I had to cut about 2" off the end of the pipe pieces that I fabricated. My custom made extensions fit perfectly now! I sent those pieces out with the headers to get them coated as well. I can't wait to hook it all up again for good!

 

LB68 - I also had a clearance problem with the idler arm... not surprising as we both have 68 L36s! and same headers. I moved the idler arm 1/16 inch.. did not affect steering/alignment. I bought mine from JetHot direct, I think aound $570 delivered with forum discount. Couldn't beat the price! I am going to read your description of how and with what you connected headers to rear pipe again.... could you post a pic? I still haven't figured that one out. Currently have flexpipe in there.. :( MJ


do you mean these things? I was afraid to buy these because the last thing I need is ANOTHER part that doesn't fit!! :lol: But if you say they fit I may give it a try! :)




[Modified by MNJack, 4:42 PM 8/4/2003]

 

Hey Mark!
Yes those are exactly the pipes I used. They don't fit out of the box I'll warn you. I cut the tubes in the middle between the bends and then welded in the 3" section of 2 1/2" pipe. If you're not set up to do it I'll bet a local muffler shop would do it for you for not too much $$$. This increases the offset so that the pipe will run between the collector and where your stock exhaust clamps up at the cross member. You may also find that you have to cut a couple of inches off of the end where it clamps up. My pipes are at the shop to get coated now, but I'll post pictures when I get them back.

I didn't think to try to move the idler arm but I still don't think I'd have gotten enough clearance. Have you noticed if your header pipes have rubbed at all? I know that the motor will torque over on the mounts a bit, but I wasn't sure how much to expect.

 

I know headers are the best way to go for performance, but after going through hopping up the '74 with small block toys I think you guys are totally nuts. Just humoring myself, so no one take it wrong. It's interesting to read what you are going through and reminds me why I will leave the '71 alone.

 

I purchased the Hedmans.

Ummm... In my 70 I don't remember having to do anything like that. I did have to remove clutch linkage and that was it. No removal of engine mount bolts, lifting of engine etc. And both headers will comfortable fit in from underneath the car. It was about the easier header installation I could ask for.


[Modified by 70PurpleLS7, 10:16 AM 8/5/2003]

 

Cant speak for the 70. I have a 68, and there was no way I was going to install the drivers side without galling the coating unless the engine was lifted. Hey, it only takes about 10 minutes of easy work, and is worth it for the ease/care of installation

 

I also have a 68, and I had to unbolt the driver's side engine mount and jack up the engine 2" to remove the exhaust manifold. I had a very frustrating experience trying (unsuccessfully) to remove the unbolted exhaust manifold before finally using that trick. The engine was back down for the header install. MJ

 

I have a set of Sanderson jet coated on my 71 BB. They are block huggers, the fit was very good and they are the best quality I have seen so far. My heads are raised port design, so it made it tricky to get them to fit with the alt brackets and PS bracket. Check them out on the web at http://www.sandersonheaders.com. You won't be sorry, very good product. I can email pictures if you would like to see them on my motor. Mine are two years old now and still look great and no leaks!

 

I just put Hooker Super Comps (ceramic coated) on my '71 big block. They fit fine and I didn't have to jack up the motor. Both sides went in from the bottom. I put flex pipe between the collectors and stock pipes to drive to a muffler shop and get permanent pipes made, about $90.

Clearance to the plug wires is a bit of a problem. I put on Taylor Spiro Pro plugwires and have fiberglass boots on #1 & #3 sparkplugs to protect them. That seems to work okay so far.

 

Save your stock manafolds, hard to come by,and expensive.

 

How about these? http://www.thorleyheaders.com Click on applications, GM then corvette 396-502 = #THY-360

[Modified by marky mark, 9:37 PM 8/5/2003]


[Modified by marky mark, 9:38 PM 8/5/2003]


[Modified by marky mark, 9:40 PM 8/5/2003]


[Modified by marky mark, 9:41 PM 8/5/2003]

 

cant say for a corvette but, I had a thorley header on a jeep and the quality wasnt very good. Im not exactly sure what the difference between the hookers and thorleys are but on theyre website it says they only fit non air conditioned stick shift cars. Hooker headers are also equal length. just a few thoughts

 

Good point. Maybe it's better to go with the well known brand.

Thanks, Mark