hdal

Orig owner,34,000 miles,3.55 gr th-350,eng runs strong,no cat/smog eqiup and off-road muffls.Car runs amazing just looking for the pro's&con's of a nice set of headers vs leave it alone? Hoping for better g/mileage and of course hp,whattaya guys think should I jack with it or leave the exh stock? Thanx Hdal

Little Mouse

It depends on what your willing to spend for good headers and copper header gaskets. Original car though with not a lot of other engine mods. Question is the headers will only net you a small amount of extra power by the time it goes through the drive train to the rear wheels with an automatic car. So if you gain even 20 hp at the engine it might only be 14 at the wheels. Is all the expense worth that to you ? If you have got rid of the terrible exhaust system behind the exhaust manifolds on those yr cars that is your big gain for you the headers not as much for you. If you were installing better air intake flow parts like heads and better camshaft then the headers would come more into play for you. Personally i would not mess with the headers without a lot of other power mods added. The way to better gas mileage for you is to put in an overdrive trans this will also give you far better acceleration to boot. Instead of spending $300.00 plus for a decent ceramic header put that money in an overdrive trans.

OMF

'78's will never have the same value as a chrome bumper C3.....it's a hobby, so do what you want with it. Mine's a '77 and I'm doing what I want with it, although I do keep the stock parts....just in case

hdal

Interesting responses. That's why I asked,big deal or not? I've had the car fo eons,just wondering if the outcome is worth the expense and time! Headers just clean things up a bit,don't want to hurt the value of the car tho..............Hdal

hpxt

I have a 78 too; changed the top end and added dual exhaust. Don't know what it did for hp or mileage, but the dual exhaust was one of the best up grades I made.

bluedawg

Go headers, they're the first mod on any small block I've owned and probably only cause they are usually under a grand and add both performance and sound.

hdal

Good responses,thank you. The eng does have dist recurved,big-air Morroso a/cleaner and re-jetted Q-jet.I believe a nice set headers will really on-cork the eng. It sounds exceptional with GM off-road mufflers on it now. Who makes quality headers and what are most using? Hdal

Little Mouse

Hedman makes an "Elite "header for vettes with a 3/8 thick head flange, thicker gauge tubing, ceramic coated and another important part to them a ball flange at the end of the collector instead of a gasket. Ball flanges are what modern cars use. It uses 1 5/8 tubing size ideal for low and mid range torque on a 350 size engine.

Hooker headers owned several sets on vette's and camaro's they give you 5/16 head flange, thinner gauge tubing and gasket collector flange. Or as i like to say the most over rated thing since teenage *****.

hdal

Mouse,I was just in the Headman web,does the ball mnt kit come with the headers as std? Some comment said rt si hit idler arm,you have any problems? Work with fact air? Hdal

Shark Racer

FWIW, back when I was running the Goodwrench 350 (which is pretty much identical in configuration to a 78 L-48 - same cam, same heads, rated at more static compression ratio but the figures are pretty questionable as numerous people have found the compression to be lower than advertised) headers made a significant improvement in throttle response, low-end torque and mid-range power. The "butt dyno" was backed up with an average of a 0.7 second improvement 0-60.

I would not hesitate to do them on an L-82 - the L-82 will take even more advantage of the power.

couperdecar

If you want better fuel mileage and WAY MORE bottom end grunt, put in a 700R4. No one even needs to know. Adding the 700R4 is like changing out your rear end from 3.55s to 4.31s for first gear or to 2.48s for the hwy. To take advantage of your headers you have to wind up the engine to 5000 rpm to gain your 5 hp, so about 1 hp/1000 rpm. You won't be gaining 5 hp 'off the line'.
Once you switch to an od tranny you'll

7t9l82

My 79 has 14k miles and that didn't stop me for a Second. That's why I like the later cars, they have no value for the most part.if you want a top flight car get a chrome bumper car.

hdal

Ow doggee,all good points! I'm just stuck on the"do I really wanna mod an orig stk anniv car". I'd say the C3's have a bit more to go in age before their values go up.I just wanna drive the car more instead of sitting in it listening to the Doobie Bros on the 8-track while in the garage,lol. The 700r4 trans swap is on my radar also. The header swap just adds more attitude to the car and with it better eng crispness. Man must be the summer heat,lol.........

Little Mouse

Have used headman headers and helped install others but have not used the Elite. Ajrothm put a set on his 69 when he had the SBC in it so PM him. He did complain about the paper (i call them ) header flange gasket. But all the companies throw a cheap gasket like that at you.

Its no secret that the thicker a head flange is the better it can seal. The ball flange is another advantage so is the thicker wall tubing. Also thicker wall tubing can allow better welding. Headman does make the Elite for vettes and camaro's. But one main reason they came out with it was for things like motor home's that create a lot of heat more long lasting endurance needed. We will call it a more heavy duty header.

With SBC there is rarely a problem with fit in the brands BBC is where things can get bad. I don't want to start cussing about the hooker's i put on my 73 BBC vette. But you can ask Lars about a set of hooker SBC side mount headers he bought for his C2 vette. What he went through nobody should ever have to.

Spend the bucks for some copper head flange gaskets and there reusable.

7t9l82

id have to call B.S on the 1 horsepower per thousand R.P.M figure . and 5 H.P. total

Shark Racer

He probably wouldn't gain 5hp at the torque converter flashpoint (2000 RPM or so), but he'd definitely gain 20lb-ft of torque.

I know that somewhere, sometime long ago someone you trusted or perhaps a group of people you trusted taught you that headers are bad; there's plenty of reasons that are true, such as:
(1) They're not original (if you care).
(2) They take up more space in the engine bay.
(3) They generate more heat (probably not true if properly insulated).
(4) There are legality concerns with some/many headers in many regions.

However, reasonably sized long-tube headers will increase low and mid-range torque on a small-block engine. The stock manifolds are horrible.

FWIW, switching from the stock manifold to 1 5/8" headers was a much more noticeable improvement than going from the TH350 to the TH700R4. The OD gear was a very welcome addition though.

couperdecar

[QUOTE=Shark Racer;1590028170] I know that somewhere, sometime long ago someone you trusted or perhaps a group of people you trusted taught you that headers are bad;


Headers are bad? I've got headers on everything. All my toys
ended up with headers. But they all ended up with performance cams, heads and carbs.
Maybe 5 hp is a wee exaggeration. Lets call it 15hp. Maybe 10 ft/lbs of torque.
But because of a steeper 1st gear in the 700R4 you have a torque multiplier to the rear wheels
of roughly +20% over the TH350

And I'd have to disagree with you that the stock Ram Horns are horrible . For a 180 hp engine they
are more than adequate and they're probably the best that chevy made for our small blocks. I had people
lining up when I went to sell them. And that's no exaggeration

hdal

Don't be arguing guys! I'll prolly do the Headman"elite"headers 1st then the 700r4 tranny.I could then tour the USA with a/c on at 2,500 rpm's,I'm all in......... Hdal

Little Mouse

I put a set of hedman 1 3/4 tube headers on my 66 vette back in 1975 put them on some camaro's and pickups no problems with the fit all SBC.

Elite work's with a/c. if you had an older vette like a 69 with a/c i believe you would have to get the special bracket for the R6 compressor that set over the top of the right valve cover. But on your 78 with the front round a/c compressor mounted off the head don't believe it needs anything. There may well be one for a stick car and a different one for an auto car.

The ball flange is welded to the end of the collector.

PM ajrothm and talk to him about them.

I ordered a brand new 78 L/82 4 speed. Only put 500 miles on it paid one payment of $306..00 on it sold it for the same price i had paid for it. At that time the new changes were real popular and the cars were being bought outside of California then being sold at $2.000.00 over list price in California. Now it was a $12,400 list price car so $2,000.00 was big money back then. At the time i also had a fully loaded new 78 454 3/4 ton silverado pickup. I decided i did not like the vette that well and if I remember the payments on the pickup were around $120.00 plus insurance on a vette for a 25 yr old and the pickup. I could afford it but decided did not want to. I had already spoiled myself by then with two BBC cars by then.

OMF

I wouldn't do the "Headman Elite" headers....I had a bitch of a time with fitment.