I purchased a 1974 convertible. When I told a friend, he replied that he never knew that I wanted to be a mechanic. It all started when spotted her on a Toyota dealership's used car lot. The previous owner had traded it in with an Avalanche for a Venza. My wife spotted it on the way to the grocery store and quipped that we should buy it. We even joked about it that evening. A week later, after much hard thinking about what I wanted in a "fun" car, what my wife wanted, and the price point I was test driving it. I am a tire kicker. When I looked at the car on the lot I couldn't have told you a thing about it. When I first drove it I was a little scared of it. I took it to two different shops to have it assessed, a restoration shop pre-purchase and a Chevy garage post-purchase. Both have declared it in fairly good health, but pointed out some repairs that need to be made, changes from it's stock condition, and the possibility of future upgrades.



- Convertible with hardtop
- Factory dark brown, repainted black. Medium saddle interior.
- Stock L48 (numbers matching), with aftermarket camshaft and headers
- Rochester Quadrajet carb
- TH400 transmission
- Base trim, no AC, etc.
- 64,000 miles
- (Excepting headers) stock exhaust, 2 inch pipe, aluminized mufflers





An interesting aside, one of the previous owners scribed the VIN on all of the glass.

Things That I Know (or Strongly Suspect) Need Repaired/Replaced:

- Radiator core support is rusted throughout the bottom
- Rear shocks have leaked the oil out
- Suspension bushings are worn/roughed up
- Left muffler baffle broken (rock in can rattle in area of muffler, exhaust spills out of muffler instead of puffing out)
- Oil leak on the passenger side near rear of engine.
* It's enough to smoke when it drops onto the header, and has been going on long enough to grease up the underside of the car.
- Transmission cooler line is leaking
- Passenger door/striker needs re-aligned, doesn't catch striker correctly and binds the lock
- Lock **** needs reinstalled on passenger door
- Clock no longer functional
- Oil gauge not operational
- Windows and door seals need replaced, deck lid looks okay.

Minor Gripes:

- A previous owner stuck an amp behind the passenger seat and a speaker set under the deck lid.
- The stereo jack line was run out of the shifter console (aftermarket retro-looking radio)
- Various nicks in the paint, some stubborn water marks, minor cracks in fiberglass near front air dam.
- Bit of stitching loose in soft top.
- Wear in the seats, some of the vinyl has worn out.
- Small crack in shift console.
- Blows hot air no matter what air setting you have the blower on. It'd like to melt the soles off your shoes.

Problems I'm Currently Having:

- Starting
* It takes a few cranks to start it, and usually it will stall out.
* Once it starts, and maintains power, it idles at 1500 rpm in park. Usually shifting to drive/reverse causes it to stall.
* I have gassed it, shifted to drive, and got it to sit at 600, then shifted it back into park and had it idle okay.
* It has idled and driven itself at 10 mph. I promptly returned to my driveway.

Things I've Done:

- Changed oil and added as needed
- Checked transmission fluid level
- Tightened valve covers with the T handles
- Reworked the driver's side lock (it jammed locked on the striker one time, had to take the whole door apart) and replaced the door seal
- Painstakingly washed, polished, and waxed

I have the rest of the door parts and a new air dam in my garage ready to be installed. On the recommendation of this forum my first purchases were the owner's manual, service manual, and the AIM. I've since picked up a few other restoration and weekend project books, along with some 350 SBC rebuild books. I have a lot more knowledge then when I started at the dealer lot, but no experience turning a wrench to back it up.

Let me revisit what I want out of the car. I want a fairly reliable roadster that can make weekend drives, and every other sunny day take me down the road to work. More concrete, I would like to drive it out to Carlisle, PA in August coming from southwest Ohio. I took it on a long drive over the 2012 Labor Day weekend where the muffler gave out, the oil leak became worse, and the transmission cooler line started to leak. Before my current problems the car had some rough idle and stall issues, especially in hot weather. It drove well enough, seemed to have plenty of power for cruising about town and I'm confident in the brakes and steering. I'm less confident in the cooling system, it gets close to the red line on hot days. The shop, I had it serviced before I drove it Labor Day, suggested that my (then minor) oil leak may be coming from the intake manifold. I figure that a leaky intake manifold and a gummed up carburetor may be giving me the majority of my problems.

As I read on this forum the first thing is make sure it will stop. I figure the next thing to do is make the obvious repairs. But in the repairs is an opportunity to upgrade, and that's why I'm making a rambling post. As a point of pride, and the possibility to learn something new, I'd like to tackle as much as possible with simple hand tools and a little sweat. My stumbling point, I think, is the engine because it determines some other fixes/upgrades like the exhaust and radiator. I'd like to have as many horses and foot lbs of torque as there are cubic inches. If I replace the intake manifold, heads, and match a new camshaft that seems like a real possibility, but if you are at that point why not freshen up the whole mill? Soon you start considering the money put into a rebuild versus getting a crate engine. Go stroked, go big block, get hotter, and it seems to spiral out of control quick.

I know other people have to have "suffered" with this dilemma, and I consider myself lucky to have a pretty good car to start with. Let's say that you have $6k of budget to work with for now, what do you do from front to back on the car?

 

Any time you buy a 38 year old car there are going to be problems. Now you know why your friend asked if you wanted to be a mechanic. Sounds like you got a good car and have a good plan of attack. As others have said: Make it stop; make it go; make it go faster; make it pretty - in that order! This place is a wellspring of information. As long as you break things down into small projects and handle one at a time you'll be fine. Keep it small, take your time, do it right and don't be afraid to ask questions. I know I've asked some pretty dumb ones and always got the help I needed. Good Luck!

 

Your hard start/idle problem sounds like choke to me. It might be time to rebuild the carb.

Have you tuned the car?

 

Congratulations, looks like a nice car. As you go thru the repairs on her you will find the folks on this forum a great help, I did. as for where to begain I agree the engine will be a great place to start.Hope you can leave it as original as possible, and if your budget is 6k be ready to double that . Enjoy the journey .
Travis

 

Congrats on your new ride. If you haven't already get some of the manuals for your car to help you along. Always nice to be wrenching on a vette, and have fun.

 

Hi JC74,
New, Old Corvette!!!!! VERY NICE!.
It looks like you found a pretty nice car. It also seems like you have a pretty sensible plan.
Good Luck, and I hope the car gives very few problems and LOT'S of pleasure.
Regards,
Alan

 

Congrat's man , really well written thread , seems to me you're on the right track.

 

Fiberglass burns... vigorously. So the first project I would take on would be identifying and stopping the oil leaks it has,then cleaning the car so you can verify you have eradicated them all. After that, I would go for the "runs hot" which is possibly (probably??) related to your starting/idling difficulty. Vacuum leaks are a real issue with these cars and can exhibit symptoms quite like those you describe... both from a cold starting standpoint; and a heating standpoint. A decent new baseline tune up and verification of base and total timing would be high on the "to do" list as well.

Be sure all the radiator seals and ducting are in place since these cars are prone to overheat if things get neglected at all...

Sounds like you have several weekends of "new owner, deferred maintenance" type chores to do. Welcome to the club, and I hope you love it as much as I like mine!

 

Welcome aboard

 

Congrats and great looking Vette!

 

Sounds like you'll be having some fun with it. You're in Mason, I have friends there. Worked in WestChester for 20 years. I'm in Oxford now, and I'm probably going to Carlisle in Aug. Most likely to spring Carlisle also.
PM me and I'll give you my contact information. It never hurts to have an extra set of tools on a road trip.
By the way, from the pics looks like a nice car.

 

Nice "new" car,enjoy!

 

neat car.
I say this to (probably) every new car owner - and I'm terrible at doing it - but make a very specific plan on what you want the car to do and places you'd like to see it improved. There are so many things you can do, from restoration to mod to race that having a direct game plan would be a very good plan.

That said, the best mods I've done to my car - in order:
Wilwood brakes and slotted rotors (~1200)
FAST efi fuel injection ~1800
Comp cams, thumpr ~ 200
Intake, aluminum - GM performance ~ 200 (came with the car)
Vortec heads ~ 700 (came with the car)
Wheels/tires - torque thrust, 17" $950 (new)
Composite rear spring ~ 300
tubular control arms ~ 500
Bilstein shocks ~ 450
Side pipes ~ 700
4 speed transmission ~200 (I had 99.999% of the parts) would cost $2500 or so to replicate
I also completely rebuilt the suspension (~700) and replaced the rag joint in the steering with a borgeson joint


I did all the labor myself... and the car runs, stops and turns like a new car.

this list is far more substantial, and if you want to see a relative blow-by-blow build of the car, PM me for the blog page where it's done (Mods here don't like links to "competing" sites).

 

Thanks everyone for the replies. I wanted to post here because I think that I've lost sight of the forest with all of the trees.

The car hasn't been tuned, at least not by me. I also don't think the engine has ever been pulled out of the car for any work.

@Indiancreek - That picture of car was taken by Jungle Jims the day I bought it. You might notice the monorail in the back.

@SuperBuickGuy - That's exactly why I posted. I'm having a terrible time planning, and since a lot of C3 owners started where I'm at I figured I didn't have to reinvent the wheel.

My thoughts on the engine are that I hate to fix what is wrong, just to tear it apart again to change things. The only compromise I could devise was to fix what I have and drive the car, then start building an engine on a stand.

I think I can:
1. Re-seat the intake manifold (torque wrench in hand)
2. Clean up (I hesitate to say fix) or replace the carb
3. Replace the transmission cooler line
4. Pull the radiator and swap the support

Using ramps, cribs, jack, jack stands, etc. what are the chances that I could work on the rear suspension myself? The shocks definitely need to be swapped out since the fluid has drained out. You can see where they leaked all over the mufflers. Is it worth tackling by myself, or using a shop? Same goes for the exhaust, worth doing myself or using a shop?

 

Re-seal the intake is pretty easy, IF, you take copious pictures of where the vacuum hoses go, and label them before you remove them. That said, with the volume of leak you describe, that sounds far more like a valve cover gasket then the rear seal (which is just silicone on the rear wall of the engine block). Valve gasket is easy - 30 minutes tops.....

replace the carb, carb bases tend to wear out and cause all manner of idle and driveability problems. buy an edelbrock (AFB) carb and be done with it. if you do change the intake gaskets - get another dual-plane, aluminum intake.... besides being a lot lighter to swing over the side, they work better.

your next two make me tired just to think about it.
Transmission line is threaded through the engine, then the engine is dropped onto a bare frame (in the factory).... it is a royal pain to get them disconnected from the transmission (no room for a wrench, and you need a flare wrench to have any hope of getting it off) then it's threaded through the frame, crossmember, motor mount and finally to the radiator. With the amount of work required, seriously consider replacing all of the hard lines with stainless, braided line

The core support looks easy to remove, but you have to take most of the front of the motor and a good deal of the headlight stuff off to get out. best bet - pull the radiator, see what needs fixing, and cut and section (weld) a new piece in place....
To fix core support problems - put a tie bar that ties the upper control arms together... it'll stop the core support from flexing (as much)

Suspension is easy the lower bolt on the shock can be a pain, but it's not a hard job, just think before getting out the BFH.

Exhaust - cheaping out means you'll have to do more work, there are several bolt-in kits available... I went with side pipes, but I like leg burns

A note about exhaust, if you put a composite spring on the car, you need to route your exhaust away from the plastic parts (or put a shield) as plastic and exhaust do not make for a wholesome combination.

 

Great looking 'vert! A lot of great suggestions and this forum is very, very helpful. Another good tool is the 'Search' feature. Just make sure you're searching the C3 forums and not everything else. My best suggestion at this point is to get a tablet and make a list of what you have to do or a "To Do" list. Go four or five pages (because the "To Do" list will soon be there) and make a "Parts" list. I usually draw a little square next to each one, so I can check it off and keep going.

.

 

Generally, the stock stuff can be made to work just fine. Most of the problems I ever had with my '74 have been caused by Bubba and his friends, not Chevrolet. The design of the car is sound.
So don't replace everything on the car with aftermarket parts until you figure out what's just worn and what has to be de-Bubba'd. A Quadrajet, for example, is a very sophisticated carb. It can be tuned for both performance and economy. Don't chuck it in the trash without a very good reason.

It's very easy to spend a bunch of money on a car, and make it different. It's not so easy to make it better.
Good luck. Have fun.

 

Looks like you got one that somebody had pretty well taken care of for a long time, then kind of lost interest.
Great thread- keep us posted on your progress.