C3 upgrades...

DorianL

solid fixture here in the forum
Staff member
What projects can be done that are fun and interesting to do on a C3 corvette?

MTIA

D.
 
Your only limited by $ available to spend & your imagination.

Many 1 off C3 Corvette projects out there right now unfinished.
Guys ran out of $$$$$$$$.
Will they let them go cheap ?
Not sure.

Big Block install into a SBC C3 should be fairly straight forward.
 
The C3's with Factory Big Block Chevie engines had special valve cover too.
Creased flattened to clear the HVAC AC-Heater Box & Power Brake Booster on such option equipped cars.
Grumpy can provide pictures.
 
a big block conversion is very very easy on the earlier c3 corvettes, slightly heavier front coil springs, a larger radiator , different accessory brackets,and ideally a stronger transmission than the th350 that many of the early c3 vettes came with, stronger motor mounts would be ideal also, but generally its an easy swap

http://www.superchevy.com/how-to/vemp-1108-c3-big-block-engine-swap/

http://www.corvetteforum.com/forums...w-to-put-a-big-block-in-a-small-block-c3.html

http://www.superchevy.com/how-to/ve...om/how-to/vemp-1110-c3-big-block-engine-swap/

once you decide on the budget and,
get a deal on a project c3,
we can start discussing the engine build,
transmission choice, and getting a big block cowl induction hood,
that gives you many more options on the intake manifold,
as it provides an additional 2"-5" carb to hood clearance ,
depending on the model and source, and youll want a corvette oil pan that provides enough road clearance,
as some car and truck oil pans extend too deep etc.
 
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Thanks, Grumpy, for the feedback. I truly appreciate it.

As I explore the feasibility and direction of this project, I am narrowing my focus down.

Hm, I will definitely stick to the early C3 for the styling. That is what ze family would want. I think I will lean toward SBC, again for the family. As I understand the C3 handles better and is more civilized with an SBC.

I do have a 4-bolt 350 hanging around, I think it will make a nice 383 build and take my sweet time to build it.

A nice 1970-71 SBC C3 seems like the way to go. Good condition... so that I can mildly upgrade power, improve the handling and detail. Body and interior will need to be in good shape.

How does the C3's handling compare to my TT, a 1973 Chevelle? The Chevelle has urethane all around, boxed arms, monster sway bars and a fast TA steering box.

Can anything be done to improve the handling?

Also I reeeeaally like my OD THM200-4R tranny. At 2000 rpm, I am doing 60 mph. At 2200 rpm, I am doing about 85 mph. Can I swap in a box with extra gears?
 
you can build a sbc and mate it too a 2004r in a c3 without much effort if it came with a th350, but the handling concern you point out, between the SBC and BBC is a total non-issue, if you select aluminum heads, water pump and intake manifold on your bbc engine build as the difference in weight between a bbc built that way and a sbc with iron heads and intake is about 30 lb IF THAT MUCH, I know several people that raced BBC C3 corvettes in road racing, in the past, I've even built a few of those corvettes engines and the feeling most guys had was the much greater torque and rapid response far, far out weighed the minimal weight difference, and keep in mind that most of those racing classes had minimal weight limits so the BBC corvette was at some advantage.
lets say either engine in good tune produced 1.4 horsepower per cubic inch,
and lets say you did not take advantage of aluminum bbc components so you paid a big weight penalty of adding 100 extra pounds ,
and, you built a sbc with a 377 built for road racing,
(400 block, 350 crank, 6" rods)
the C3 corvette you select after mods for road racing, weighed 3300 lbs
(trust me youll fight to get it that light weight and race ready)
and you compare it to the same car with a 468 cid BBC
(.060 over bore 454) which are both very common combos.
the 377 x 1.4=528hp divide that power into 3300 lbs=6.25 lbs per hp
the 468 x 1.4-655 hp,divide that power into 3400 lbs= 5.19 lbs per hp
thats a roughly 19% advantage in power to weight for the BBC powered car,
and thats not pointing out that you could build a 477 (dart 4.5" bore 427 3.76" stroke bbc ) which would make even better power.
lets say we make the cars weigh 8 lbs per cubic inch
377 x 8=3016 lbs
468 x 8=3680 lbs
here you have a 664 weight advantage for the sbc,
and if we use the same power, to calculate
3016 lbs divided by 528=5.71 lbs per hp
3680 lbs divided by 655 hp- 5.61 lbs per hp
this makes the cars about equal because the slight power to weight advantage the bbc has will be negligible to to inertial losses in acceleration and braking,
but your not restricted like that, and its a whole lot easier to get a 3400 lb BBC car built than either a 3000 lb sbc or forcing you to add weight to have a 3680 lb bbc


If you know what your doing, and can build a decent engine and drive train and suspension, with the correct brakes cooling engine,suspension mods and tires,properly set -up a big block corvette with a l88-ls7 can provide impressive race track handling and acceleration and braking.
c3l881.jpg

c3l882.jpg

c3l883.jpg
 
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The 1984 Corvette held the Record for the Best Handling US Car ever for a long time.
It was tested at 1.04 G's.
Till the C7 Z06 Surpassed.

Next best is the 1970-1/2 to 1981 Firebird Trans Am.
See How Birdmans 1970-1/2 Firebird Road Race car handles.
My guess 1.3-1.5 G's.

Besides my own 1987 C4 Corvette Roadster & my 1970-1/2 Trans Am ,
Very best handling I have driven and ran full bore was a 1979 Pontiac Trans Am with a 301 Pontiac .
301 Was a real light engine.
 
Good so. Glad to see this can be done.
yes.
Nothing really special about a C3 to me other than the 210 L-88 Corvettes built from 1967(C2 ) to 1969.

It has been the darling car of Digital Corvette.
Only a few have finished.
Zero have drag raced so I am not interested.
Bored because just show & shine.
 
Fair enough. I did my years of racing. Now I'm looking for something mild with style so my kids have something fun to drive (on special occasions). ;)
 
Fair enough. I did my years of racing. Now I'm looking for something mild with style so my kids have something fun to drive (on special occasions). ;)
A Corvette is a personal sports car toy.
You can not take the wife & kids all at once in a Vette.
Was never meant to be.
My wife lost intrest in riding in my Corvette. We dated an ran everywhere in my Vette together.
Now just my Boy Nicky & me Ride together in it.
I install a car seat for him.
 
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