Hello all,

I purchased a 1974 Corvette in 2020, been in the shop/garage being worked on mainly for cosmetic issues (leveling the hood, replacing sending unit, new actuators & hoses for headlights, etc.). She seemed to be mechanically sound so nothing major had to be done. Finally was able to ship her to Florida (Pensacola area) from my hometown in Colorado, but in the process of unloading off the trailer the engine started to overheat, white smoke started coming from the engine & bubbling came from the coolant reservoir. From what i’ve seen it’s pretty apparent it’s the head gasket- haven’t checked the oil yet but the signs seem apparent.

The reason for posting is to ask what the replacement is like, how much i’m looking at both cost & time wise, & any other general information/recommendations. I am just beginning primary flight training for the Navy, so time is limited to work on it myself due to studying and being scheduled for flights. My budget is between $3-4k.

I would appreciate any help I can get, as I am yearning to cruise around the Florida beaches as soon as possible! Thank you so much.

 

If you are organized the job will go much quicker. Searching for removed parts and trying to figure out what goes where is time consuming.
Having said that, take photos of wiring, throttle cable routing, etc. Buy a box of Ziplock bags and a felt pen. Organized all the bolts, parts removed and label the bag.

I use a board with 16 holes drilled. I put the pushrods in the board then later right back with the lifter / rocker arm it came from.

Your worst enemy will be the exhaust manifold bolts. You should start soaking with PB Blaster now. Use a six point socket and hope for the best.
If you have done this task before it can be 90% done in one day. The Intakes gaskets need scraping off and new gaskets should be allowed to dry overnight.

​​​​​​​Stabbing the dizzy and setting valve-lash is timely. I would set the balancer at #1 TDC before disassembly while waiting for the coolant to drain out.

You may want to run some test to verify it truly is a head gasket. Pressure test the radiator, check for CO2 in the coolant. See if the dipstick is milky.

 

The biggest worry in my opinion is that it's more than a blown head gasket. I've owned 2 C3 Corvette's with those exact symptoms. Both with cracked heads and perfectly fine gaskets. A new pair of aluminium heads. Headbolts, pushrods and gaskets, you should still just squeeze in just under budget. If you don't buy the best of the best heads.

 

This is an easy weekend project and with your budget you can afford to do it right: AFR 195 heads, mild Howards Cam, quality head gaskets, and you'll have a refreshed engine! A Champion radiator wouldn't hurt while you're at it too..

1. Drain coolant
2. Remove Carb
3. Remove intake manifold
4. Remove valve covers
5. Remove lifters from head
6. Remove push rods
7. Remove lifters
8. Remove head bolts, and pull the heads!

The above takes me about an hour to do. If you've never done it before and you're taking your time i'd set aside a full weekend for the job. The above advice regarding manifold bolts ain't no joke, but if you're changing the heads you won't have to fight any broken bolts out.

 

I think I'd be pulling the water pump. Vacuuming out the excess coolant that never drains, etc. This alone will take over an hour. An hour to pull heads with all rocker arms off and no coolant in the oil or bores?
Damn! Your superman!
It would take an hour for most to remove the carb and linkages while marking everything if it's their first go at this.
And the OP says he has limited time. I get that as he's looking to pay someone to do it.
Head swap at any good shop taking there time and doing a good job. I'd guess 1K in labor give or take. New heads will require pushrods and new headbolts. AFR heads alone are near his budget.
I'd be looking at Edlebrock E Street heads. Then pushrods , headbolts, gaskets, oil, coolant. Sealants, etc. Plus Labor. MAYBE squeak in under 4K. Maybe.

 

Dear cmeilner7

You come on here asking a simple basic question and anticipated a simple honest answer. You asked about changing head gaskets only.

As you can see, it's easy for posters to spend someone else's money.
The list of parts is endless for some. If you are going to pull the heads, get aluminum, then new rockers, pushrods, might as well install new cam, timing chain, headers and so forth. You are now into the thousands of dollars.

Back to your question:
Intake Manifold Gaskets less than $20
Valve Cover Gaskets around $30.
Head Gaskets, figure around $60 a pair.

Time frame for labor? Hard to say. I don't know your skill level. Perhaps you could do this blindfolded in four hrs.
However, if just one bolt gives you grief coming out, it could be a week later.

I don't know what tools you have but a torque wrench is a must.
It's not a bad job at all. As stated earlier, the rusty-corroded exhaust bolts will be the tough part.
And 80% of the time, some unexpected flaw will detour the best of intentions, known as a set-back.

The beauty of these old Vettes is how simple they are to work on. No computer, few sensors, no metric and you don't have to remove a dozen other parts just to "see" the repair part.

Only you know what you are capable of.
Good Luck

 

Some of the head bolts, particularly passenger rear are a huge PITA to torque down with the motor in the car. Just fyi.
there are many threads on here about setting valve lash.
probably a weekend worth of work for someone’s first time.
The great thing about old cars, easy to work on

 

I got the impression he wants a shop to do it for him.

 

I get the impression that he is in a hurry. And that's too bad, that one has to farm out the job.
Basic engine work can be a very rewarding and enjoyable task that is not ridiculously complicated and expensive.

 

A c3 vette makes an excellent ensign-mobile

 

If you are working on it yourself, you are probably looking between $350 to $400 between gaskets, fluids and such. For a modest mechanic it can be done over a long weekend. Longest part will be setting the rockers up.
If you are looking for someone to do it for you then figure between $900 to $1,500 for parts and labor.
This is all based on it being the head gaskets and not something else.

 

Just went through this myself. My 73 had the same symptoms. The culprit was in fact cracked heads. I went with the edelbrock E Street heads, 1.5:1 roller tip rockers and new lifters from comp cams, new edelbrock push rods and a new set of gaskets for everything.
New fluids and new filter and some miscellaneous stuff and the entire job cost about $1700. I got the heads and other parts last December when edelbrock was having a holiday sale. 10% off I think.

 

Even if you have a shop do it....you need to go rent a radiator pressure tester and see for yourself where it is coming from......this arms you from the "mechanic BS" that a lot of them do by saying things are more than what they are.....
I can do a pair of head gaskets (NEVER do one).....start to finish in about 8 hours (I'm slow but methodical)...but know some things:

1) I have yet to work on a vintage musclecar that didn't need a bunch of detail work and de-bubba-izing.....I spell these things out pretty clear while doing the job so no surprises.....but all that stuff costs....not a ton, but it does......things like shortening spark plug wires.....using studs and $50 Fel Pro valve cover gaskets.....$30 Graphite header gaskets on exhaust manifolds.....I add and do what works and what will keep things reliable in the future......I usually tune the engine too because about 1 in 10 are even close.....

2) The only way to know if a block or head is cracked is to pull the heads......if the heads are cracked. replace them with a modern equivalent.....do not screw around with stock castings unless you have an L-88 or something of that grain.....whoever does the work needs to be pretty Johnny on the Spot with this....and determine if it is the heads or block.....head gaskets show witness marks too and bad previous installation can cause one to blow.....

Jebby