I am a newbie to the forum. I have owned a 1971 Coupe with an original matching numbers 350/270 with a 4 speed manual for two years. I am looking for more reliability so that I can feel comfortable taking the car on short trips. So, I am considering having an engine swap done at a local shop. I am favoring the ZZ383/425HP GM engine (around $6500 installed). I would store the original 350 in the garage. Any input/suggestions?

 

What's wrong with the 350?

 

My guess is no horsepower.....

 

HP is definitely an issue. But, mostly I have the mind set that I would not trust the car on a trip 50 miles or more from home. The previous owner did a nice frame-off restoration. But, the engine and drive train are original. So, I do not trust the car on long trips. I recently moved 50 miles away from my office. So, I do not trust the Vette for transportation to work. Also, the Vette is a "toy" since it is a second/third car. But, interestingly, it is the slow one of the three (G8GT, WS6, C3 Corvette). So, a ZZ383 would solve both issues (reliability and HP) as long as the drive train is also given some attention/upgrades.

 

So, has the car died on you in the past? The SB Chevy engine is one of the most reliable engines out there. My '71 engine has 207,000 miles and I'd drive it across the country in a heartbeat (if someone else wanted to buy the gas ). Reliability isn't so much an issue of 'age'...it is an issue of maintenance. Things will wear out; but the major hard parts in the SBC engine almost never wear out. If the bearings and rings are good (drop the oil pan and take a peek; do a compression test on the engine), your belts and hoses are in good shape, and tires and brakes are 'up to snuff', what are you so concerned about?

I'm happy for you that you have other 'newer' toys....but maybe they have spoiled you a bit...

 

We probably need a reliability benchmark of your current mouse motor to make a recommendation. If you say it broke down on a <50 mile trip and it turned out to be a cracked distributor cap, I wouldn't buy the ZZ383. If you had another breakdown and the culprit was a torn fuel pump diaphragm, I wouldn't buy the ZZ383.

But if you said your 40 year old mill used 2 quarts of oil and fouled the spark plugs so badly it wouldn't start for the trip back home, then I'd yank it in a heartbeat and replace with a crate motor.

See where I going with my reasoning? Oft times, malfunctions are caused by external engine components. But if you're bound and determined to stimulate the economy by buying a brand spanking new crate motor, far be it for me to say STOP.

 

Rebuild your original engine and trans. Your car remains stock and you will have all the reliability you want.

 

I agree....rebuild the original. I think it's funny how the previous owner did a "frame off" without touching the motor. You would think that goes hand in hand.

 

Either rebuild the original or pull it, store it, and replace it so you can put the car back original in the future. But I have the same question as the others. What's wrong with it other than you don't trust it? Put a good tune-up on it, replace the hoses, and drive it. A leaky water pump or a failing fuel pump can be replaced a lot cheaper than rebuilding the whole thing just for peace of mind. Drive it and learn to trust it. I worry a lot more about a brake system problem than an internal engine issue. Chevy engines are pretty durable with reasonable care.

 

I take my 78 with 86K out for coffee and the cafe is 50 to 60 miles away. Lunch and dinner needs a 80 to 100 mile cruise and short trips to VT or PA are in the 150 to 200 mile range. What issues do you have with the mill? The battery die once but there are Autozones on every corner here in the East and they install them for free.

 

Peripheral failures [things attached to or associated with the engine] are NOT engine reliability problems. You will have those problems no matter what engine you have. The only things to really go wrong in the engine are rings, bearings, valve train (cam, lifters, rocker arms), and pumps; and the pumps can be replaced fairly easily.

If the 'reliability' you seek is just the car in general, then the PO who did the "frame off" did a lousy job. There are minor things that go wrong with a 40 year old car [that don't go bad on a new one], but those don't leave you stranded. Perhaps you are just not a DIY kind of guy. That is fine...different strokes for different folks. But maybe a 40 year old car is not a responsibility you want to take on. That's OK, too; but the best thing for a 40 year old 'original-condition' car is to sell it to someone who really wants it, rather than to modify it into another "run of the mill" old car.

 

Get the zz383 , youll love it. then get a 5sp trans. thats the biggest favor you can do for a new 383 engine.

 

Unfortunately, I was one of the fools that did insufficient homework PRIOR to the purchase. The car had multiple issues including engine failure within the first few months of owning it (cracked cylinder head). I gave one of the local Corvette shops a mint to fix the botched items (fuel leak from the fuel tank neck - still not resolved, rear diff leak, AC system not holding a charge, etc). I am still left with a very solid car with a nice frame. But, the car has marginal paint, large gaps at the front ends of the doors (apparently from a poor placement of the front cap - not just a simple door adjustment), and a 73-75 hood/no wiper door. But, the interior is fairly nice (red vinyl) and the interior accessaries are functional including the factory AC. I definitely bought a botched frame off (now I can recognize even the subtle issues). At the time, I had no business buying a C3 without researching the restoration more carefully and having the car inspected by an expert. I am a very trusting person - a bad car buyer. I could try to sell the car now and give up on the dream of owning one of the most gorgeous cars ever built. But, my intention is to keep the car and make the best of a bad decision. So, even after dropping the engine and having it rebuilt or swapping it for a ZZ383, I will have a less than perfect Vette, But, I can live with its defects. Obviously, I am in a situation where I am at the mercy of the experts that are working on the car. So, I am working on getting a work space, tools, and a little more knowledge. I agree - the other cars that I own have spoiled me since they have been trouble free. But, I consider myself fortunate. I just feel like I am getting nickel and dimed to death ( I can spend the $6500 it would take to have the swap done in a heartbeat at the local Corvette shop). So, my reasoning was to eliminate the stess of breaking down and hassel of leaving my car at the shop every time something goes wrong. This is my first classic car. So, I am hoping to gain some knowledge from the members even though it is a little late in the game. Thanks you for your time and input. I really appreciate your guidance.

 

If I do go through with the swap. Since the car will no longer be original, I am considering side pipes. What are the best options for side pipes on a '71 (Hooker, OEM, etc.)? Also, one side pipes are installed, how do you keep the rear valance form looking incomplete? Keep the exhaust tips in place?

 

Putting in a 383 would be great from a perf. standpoint. Chevy V8s are reliable.
Reliability has more to do w/ ignition, belts, hoses, thermostat, battery... the main point here is besides the 383, you need to think about which ig. system & if you keep points you need to know how to adjust them.

The reason given for side pipes over & over again is looks, some get tired of the noise so leave the back for now. Something else that could be done is to add caps to make the side pipes open or closed.

 

Hi m2004,
If you do decide to add side exhaust, in order to complete the job the rear exhaust cut-outs do need to be filled. There are various ways to do this, all involving body and paint work.
Various venders sell a valance panel that replace the original and has 'tabs' that fill the part of the opening that remains in the quarter panel. Even these require body work and paint to make a good appearance.
Here's a picture of a 71 with a 69 side exhaust valance, and the quarter panel openings filled. The seam is the way the factory did it in 69.
Regards,
Alan

 

I am not concerned about the noise. The risk of burn would be an issue. But, I would get them jet-coated. I was under the impression that side pipes would give me more options for the manifolds. I was hoping to maximize the HP and Torque gains with long tube headers. I was told that the stock exhaust would make long tube headers a difficult fit due to clearance issues. I wonder if there are electric or manual cut-outs or something similar to turn on and off the side pipes and re direct the exhaust flow to the back mufflers? Thanks for the input and very good points!

 

Alan:
That is a very nice clean look and a great solution. Thanks! Michael

 

if you are worried about burning you leg, side pipes are not for you in my opinion.

 

I have long tube headers.I don't have any fitment issues with the stock exhaust.Who told you that.No offense but if I couldn't work on cars I would have bought a fully well restored car.You might come out ahead to bail out and get a better car.There is always someone who can't see past the problems because they have always wanted one,that will buy it.