Hi All:

I recently purchased a 76 C3, it has the L48 original motor & Auto Trans. Only mod is headers, and K&N filter. It came with a Speed Pro 1013R Cam Shaft in a box with a set of lifters. I'm wondering if this is worth installing to wake this engine up a bit, or just wait, and spend money on a GM crate motor later.

Any help appreciated.

Myles

 

If you are just waking up the L48 then I would get it running properly and learn the engine before making any changes to it. If you are new to the Corvette then just get to know it before modifying it. The headers probably help a bit if they are long tube headers.

We see a lot of people buy a Corvette and have a list of modifications to make the Corvette "more fun". This is not the nest way to get to know a car like your 1976 C3.

I bought a 1968 C3 out of a barn in Irvington, VA back in 1991. I did not know very much about Corvettes back then but learned fast. My wife and I drove it to Corvettes@Carlisle and during a downpour (without AC) in a semi sealed convertible and we learned that our rear wheels were "steering" the car. It scared me to death and I drove home carefully and then removed both trailing arms and sent them to Van Steel down in Florida. After replacing the bearings and bushing in the rear then I had to work on my Brake system. My master cylinder was way too sensitive and it was scary to drive the car. While coming home in 70 mph traffic I pushed the brake pedal and it wouldn't budge. Again more excitement and terror... Fortunately the FIRST thing I did on my C3 was fix the emergency/parking brake and with the four speed I was able to get home. The C3 is a Great Corvette but there is a steep learning curve when you first get one.

Eventually the car became dependable enough to use to drive to work and it did not surprise me until one day with the top down cruising along at 70 mph the non-functional radio turned on and started playing the famous song "Christine" played extolling her love for the owner of the car. Then a minute later the radio turned off and was never heard again. "Don't let any ******* get between you and your Corvette"

Your engine can probably be made to make plenty of power. I swapped a small block into my C3 while I took almost a year to rebuild the Big Block. I bought a $300 engine that turned out to have the Camel Hump heads and LT1 Block. If you take your time and rebuild the engine over a winter or something that has worked out for me in the past. Anytime you build an engine in a hurry you pay a whole lot more money.

Take your time and "learn" your Corvette and go through every system in the car and replace all the fluids, belts and hoses. Fortunately the C3 parts world is still decent, the C4 parts are drying up every year. If you live someplace near a good Corvette event go see them and establish connections with re-builders and parts suppliers that specialize in your Era Corvette. Paragon is a great one for example. Corvettes@Carlisle is the third weekend of August and is one of my favorite Corvette events. I have met so many people and learned a lot from this experience. The deals are there as well, you will find lots of parts both used and new as well as anything you are probably looking for.

As per your cam that came with the car I would probably put it into the garage on a shelf. Cam technologies have made HUGE advances in the past 30 years and it might not be the "Hot" thing to put into your Corvette any more. I would wonder why the Previous owner did not install it...

Good Luck and Best wishes!
Chris

 

Hi Chris:

Tks for the advice. You are right. I don't know this car all that well, so perhaps I will drive it for some time before I do any further work to it. Its in for an insurance inspection right now. It needs new pads & calipers as they are leaking I'm told, so we will start with that, then I can drive it some more.

Myles

 

OP
First ... Fix the stuff it needs ... there's probably plenty.

Even brand new, '76 L48 has very low compression ratio ... And a small cam with short duration.

1013 cam has about 20* More Duration and about 0.045" More Valve Lift.

Auto trans, Low compression car plus much added duration will perform poorly on street.

So ... any significant cam change should be done in concert WITH a significant compression increase.

If you can find a good used set of either L98 or ZZ4 heads (both w/ 58cc chambers) ... coupled with your 1013 cam will really wake OE '76 L48 up.

 

OP
Suggest download this vehicle information kit (110 page pdf) from GM ... lots of details direct from GM for your '76 vette ... free of charge


https://www.gmheritagecenter.com/doc...t-Corvette.pdf

 

Hello there Myles!

Corvettes are one of the best hobbies out there in my humble opinion of course. My daughter and I have been working on restoring our 1988 C4 and having a blast doing it. I have been using RoackAuto for many parts on this Corvette, I keep waiting for them to ask for a picture so they can make a magnet with my car on it. I have spent enough to justify it.

Anyway, RA has good prices and fast delivery. I was able to put slotted and drilled rotors on all four corners of my C4 for less than $500 including rebuilt calipers. When you do your brakes be sure to flush out all the nasty fluid from inside the system. Older cars will have rust in or on their brake lines and can fail if ignored. When I first got my C3 I had to replace the crossover line in the front of the Corvette to get my system to hold pressure without ANY leaks.

I am not sure on the 1976 model C3 but my 1968 C3 has the parking brake inside the rotor in the rear wheels. When I bought the car it did not work, I am a stickler for a parking brake so I fixed it. They make Stainless Steel brake parts for that application, I would strongly consider replacing these parts if the parking brake is not secure. The SS parts last a lot longer and are naturally more expensive!

The trailing arm's need attention too on older C3's. There are bushings where they attach at the front, when they wear out the arm moves around and makes noise. Then the rear wheel bearings are built into the trailing arm and when they wear out (They all do) the rear end will help steer the car which as I mentioned earlier was terrifying at first. There are a lot of rubber bushings on these cars, most are worn out due to age. Replace the ones you can and get help with the hard ones.

How is the carburetor on the engine? If it is original then you might want to have Lar's take a look at it for you. I hear his name a lot and I understand he is "The Man" when it comes to quadrajet carburetors. Older carburetors usually need some help unless owned by a mechanic.

If there is anything you need help with please feel free.... The hoses that connect the calipers to the brake system probably need to be replaced. If you need them buy a set of D.O.T. approved SS braided hoses and not the inexpensive Chinese knockoffs. Classic Tubing is a great resource and located in NY state. The SS hoses make the brakes work better as they don't expand under pressure like older hoses can. They help your car be safer....

Best regards,
Chris

 

Tks for all the reply's, and advice guy's.

The Car is in really good shape I believe for 43 yrs old. I'm sure over time I will find some things to replace. Winters are long up here. The former owner owned a NAPA auto parts store up here in Canada, and has had the car for at least 10yr's, he may have sold it due to his vintage, and didn't want to put any money into it any more, he let his baby go a bit , but I won't.

Myles

 

Tks for all the advice Chris. It is appreciated.

Cheers

 

If I cant find any L98 Heads, or ZZ4 Heads up here, any suggestions for aftermarket.?

Tks,

Myles

 

ANY modern head with 58-64cc chambers and 165-180cc intake runners will be light-years ahead of the stock 624 OEM heads it came with.

 

are you sure it's the new cam in the box?

it might be the original cam and lifters after the cam swap already.... just been put in the box for storage....