Since winter is coming up, I have a few things in mind that I would like to do to my c3. As a 18-year-old, money isn't flying out of my pockets but I have saved up some spending money. After driving my c3 around for a little over the months I realized they are kinda slow and sound iffy. Yes I know, corvette parts are not cheap, but I've started looking into some performance parts. So, should I start looking into cylinder heads and headers or intake manifolds and a carb? I don't necessarily want this thing to be a street demon and I don't plan on engine swapping, just for the car to sound nice and have a little get up and go. A lot of my learning on cars is by myself and through this car so I don't really know if there is an order I should buy these parts. From what Ive seen, a decent set of heads is around 800$-1000$, headers can range from 200-400, intakes 300-500, and carbs 200-600. Any recommendations on where to start? Nothing outrageous on price but something on the average/cheaper end.

If you have any other recommendations please let me know, like I said I'm not the most mechanically inclined so any help will be greatly appreciated.
Thanks!

 

What do you know about the health of the bottom end and rings?
Have you done a compression check?

It would really suck to buy some go fast goodies, and spend the time installing them, only to have a rod start knocking, or it starts using oil because of the rings.

The heads don't flow that well, and the compression is low.

It already has a four barrel and manifold, maybe a good cam and headers/dual exhaust.

If you can find a cam that works with the heads and compression you have, and a good tune on the carb and distributor, it would cost less than heads.
I don't think the factory pistons are worth putting a good set of heads on top of.

Just my opinion, others will be along to give you theirs.

Search out some posts by Jebby, he has some good tips on getting a bit more power out of the L-48.

 

welcome

guy is right, bottom end needs some thinking about.

many many people ask what you are.

basically you need to understand what makes power.

you can get headers, long tube
re-curve distributor
good dual exhaust

these will be useful in whatever eng upgrades you want

good luck

 

In terms of $$ for HP, cam and heads will yield the best band for the $$. On the cheap look around for a used set of aluminum 170cc-195cc heads with 64cc chambers. That size head should add 1 point of compression. Then stick something 264-268 duration cam with ~.450 lift. Headers will give you 10-15 HP, so I would put them low on the list. You will also need longer hardened pushrods with the aluminum heads. The cam and heads are worth an easy 30-40 HP.

Vortec heads will work as well as aluminum for your application but you would need to use a vortec intake so might as well source aluminum heads. Intake manifolds won't help with the HP much in your application. Cheap china heads will work, but you need to have them checked by a machine shop before putting them on.


Before doing anything take the time to do a compression check and make sure the rings are solid. Swapping cam and heads isn't trivial, so make sure you have some seasoned help available.

 

L48 suffers from a few issues. Low compression, really crappy heads, a factory exhaust system that really sucks (if it's still on the car 46 years on) and a distributor that simply isn't curved correctly for performance applications.
A set of heads will help a bit with compression, but changing out the pistons to flat tops plus better heads will get you into the ball park. Heads alone not so much.
loose the stock exhaust if it's still their. put on a good true duels exhaust. even with the factory manifolds it will give you a boost.
A relatively mild cam might help a bit with the low compression.
Bottom line, put a budget out there.
just saying you have little money is not enough. For some little money is 200 bucks.
For another it's 5 grand.

 

I agree with starting off with a compression check. Do that first.

You might also do an inventory of what you have on the car now. What’s on there that’s original? After 50 years it’s likely that some non-OEM equipment has been installed. Has the entire engine been swapped at some point?

 

Not sure what emissions are like in your state, but removing the restrictive cat and mufflers, in combination with recurving your distributor would make a noticeable difference in power and responsiveness.
Recurve kits are like $15
getting an exhaust shop to straight pipe your car, a few hundred.
in my opinion, headers add horsepower at the high rpm’s, putting a $400 set of headers on is not going to make a noticeable power difference at typical driving rpms/throttle conditions.

 

If your car doesn't have a manual transmission, solve that problem first. Your car will feel ten times quicker and be about a million times more fun to drive.

And email @lars for his tuning papers before you do anything else. PM me if you can't find his email on the Forum.

 

A change in rear gears is the best option IMO

 

Very simplified list:

Top end - Heads, intake, dizzy, mild cam (nothing radical), and good exhaust should make a pretty noticeable difference that you can feel. It won't be a drag racer, but it should give you a boost in performance.

Later on - Bottom end - hypereutectic or cast flat top pistons to take full advantage of the top end.

 

After reading, I think I'm going to go the striaght pipe way and run the stock manifolds on it for the time being, Ive also seen something about recurving a distributor? Im currently in college and go home every other weekend so I try and plan everything before I do anything. The odomenter says 14,000 miles and the car had been garaged kept for about 15 years before I stumbled upon it. It sat on cracked concrete so the frame was absorbing moisture but I would say it is about a 6/10(10 being brand new). It had a underspray on it and the spray has cracked all over the place and there are a few nickel sized surface rust spots. When the engine is running it shoots out white smoke but not alot,(hope its not a valve seal problem). Ive found a front end suspension rebuild kit, springs and have already replaced the shocks. So for the time being the suspension I say is in decent shape. Ive done some more research and should I be intrested into a electric dual fan radiator or do you believe that is further down the road? Would there be any other supporting mods If I were to go the cammed route or any mods I should do before going for hp? I believe Im getting ahead of myself but Im trying to piece everything together before I start buying parts.

Trying to give you, and everyone that reads a brief summary on the car.

Budget- 600$-1000$ for the moment
I have patience and can wait.
But as of right now what is the best way to start?

Thank you again for the help I can not stress how much you and many other people have helped me so far, I really appreciate it!

 

With a budget of under $1K for now, here is your best route to improving engine power levels:

Get a distributor advance curve kit. Google that to see what it does. Install that and time your engine for 38 degrees total advance, vacuum advance not included, and you will have a noticeable boost in performance.
Replace your spark plugs, wires and distributor cap.
Get your carburetor working properly. This might require a rebuild. What carb is it? If it is a Quadrajet don't let anyone tell you its no good.
As you mentioned - put a full dual exhaust on the car. Headers are better than stock manifolds for performance, at all rpm levels.
Also your tires and brakes probably need work so you'll be spending money there.

 

OK, Now we have a ball park of what you wish to spend. However no real idea of what's on the car now.
Assuming it's totally stock for the time being.
Back when I bought my 77 many years ago it was factory stock right down to the wingnut on top of the aircleaner.
It was a Dog with a capital D.
One of the first things I did was lose the factory exhaust with the restrictive cat. I put on chambered exhaust that is still on the car all these years later.
Of all the things I have done to the car, this made the single biggest difference.
at that time I had also tuned the car. (recurved the distributor).
These 2 things you can do in your current budget.
Now, the white smoke.
White smoke generally means a cracked head or blown head gasket. Not a valve seal. thats oil smoke, generally a blast of Blue/black smoke from valve seals on startup.
White smoke is really bad.
these cars are notorious for cracking heads.
Ive had 2 77's, one I still have. Both cracked there heads.
New heads may be in your future. And installing properly is no small job for the inexperienced. But can be done.
If you are certain it's white smoke your first step should be to get your cooling system pressure tested and tested for exhaust gases in the coolant. Not expensive to have done if you don't have the tools. Some auto parts stores rent or lend such tools as well.

 

post pics. carb, distributor, engine ID stamp pad. you can't justify spending any noney on anything untl you know what it is replacing. does it still have the catalytic converter? do you have emissions inspections in your area for 1976 cars? has it ever had a cam or timing chain replaced? how old are the 4 rubber brake lines at the brake calipers? you may want to get a cheap endoscope and get a peek at the piston tops. engine could have been redone with flat pistons or domed ones even before you were born. and a lot of these cars were put together by somebody who died, gave up on the car and let it go cheap, got divorced and ex sold it, etc. so the history on a lot of these is gone and you need to research your car before throwing money at it. the 4 rubber brake lines are crucial and most likely older than the 15 years it sat. they gotta go. drop the pan and pull the timing cover cover. many of these cars still have the original nylon timing gear that started to let go at 10 years of age. i am reluctant to try to talk you thru messing with rods and mains. not difficult but possible to eff up. replace the oil pump. now you know you have a good timing chain and gears and all the gear teeth out of the bottom end. i would start with timing it correctly and do the headers. everything you do later is gonna be restricted by the manifolds. get it timed right and the carb right and you will be pleasantly surprised. you may even want to pull the heads and check them out. cracks can usually be seen. bad valves can be found by filling the ports with warer and seeing if it drips or pours past the valve. buy a valve spring compressor. this ain't the last set of heads you are gonna be messing with.

 

I would recommend you stick to something basic that will yield you some decent Hp and not leave you having to worry about always running low on gas. Invest on a nice exhaust system. Start with some long tube headers, get rid of your cat and put some straight pipes into good sounding mufflers. If you still have some smog control stuff on the engine, you might want to get rid of some of that. I would also check to see that your car's carb is tuned properly and also curve your distributor. This alone should wake your car a little and sound pretty nice.
Once you change cam, cylinder heads, intake, carb and some other goodies. Your car might not like the 87 octane anymore.

 

^^^^^^ this ^^^^^^^

A new carb will be choked by the old cam.
A new cam will be choked by the old heads.
Headers don't choke anything. Best bang for the buck is exhaust system.

 

I'd save your money and get into a later model that has more power. Any $ you spend, you'll probably never recover when you sell. The Vettes built in the mid to late '70's had detuned engines due to the "gas crises" when there was supposedly a shortage of gas on the market. Horsepower was deemphasized by car manufacturers while they emphasized MPG. (Obviously this was well before your time and perhaps you've never heard of it.) I had a '76 and while it was a fun car, it had no pep. 0 to 60 time is about 8.5 secs for the base engine. (Yikes) There's probably not a car manufactured today that doesn't have a better time. Just my 2 cents. Good luck...