Hello everybody. I intend to buy a driver quality 1973 Corvette. I live in Switzerland and there is basically no market for unrestored Corvettes around here. So I’m trying to find one in the U.S. and have it shipped over to Europe. I have seen several interesting and reasonably priced cars with crate engines or otherwise modified engines. The problem is that my “Road Traffic Authority” (where technical inspections are done and cars are registered) does not accept modified engines unless there is a paper or certificate that shows that the engine was designed for that car and that the complete package is roadworthy. Emission is not an issue for a car from 1973 or older, but power is. If rated power of a crate engine is more that 20% above stock power then a certificate is required.

I have understood that earlier small block C3s had stock power levels as high as 370 HP (1970). And unless there has been any downgrade in brakes, suspension and similar components over the years 1968 to 1973 I think it should be perfectly OK to have a ZZ4 engine with a rated power of 355 HP in a 1973 Corvette.

Questions:

1. Is there any official paper or certificate that shows that a 1973 Corvette is roadworthy, at least in the U.S., with the power from ZZ4 or similar crate engine?

2. Did all 350 CUI Corvettes between 1968 and 1973 use the same brake, suspension and similar components? If yes, is there any official document that I can use to prove this?

Thanks

 

the highest HP rating for a 73 corvette was 275 HP for the 454 cu in engine and 250 HP for the 350 cu in engine

 

how do you show to your inspectors that power is less than 20% more? and how do they show it is greater than 20% more in order to fail the inspection?
its a great philosophy on paper, but how does one prove it?

 

^^

 

Sometimes the crate manufacturer provides estimated horsepower numbers for their builds. Sometimes they actually dyno the motor and include the dyno sheets with the engine. If Pamotorman is correct you should be good for 300 hp. I'm pretty sure any crate mfgr would tell you their SBC fits a 73 corvette.

 

All 68 to 85 Chevy small blocks interchange. The 68 has a few strange parts that are 68 only. The parts will fit on a crate motor.

A crate motor is as good if not better than a stock 73 motor. Newer materials and better machining usually make it run better and produce more power. They are available from 250 hp to 425 hp from GM.

In 1972 the HP rating went from NET HP - no accessories or exhaust to SAE rating - with accessories , air cleaner and exhaust - mufflers. Thus the horse power rating dropped. At this time the compression rating also dropped - thus lower HP ratings.

The actual differences are not as great as one would imagine if rated the same way.

If you are buying a car here I would ask an NCRS member or judge to evaluate the car and send you a report. They list services in the NCRS journal.

 

how do the inspectors know what hp a motor has with out a dyno test?1965 thru 1982 had the same brakes.you could check a parts book to prove the same calibers.if its that much of a problem to import a car ,I would just find one that had a numbers matching motor.

 

 

I think that this ^^^^^is your best bet right now. I agree with others not knowing the details of your inspections about how can the inspectors know much about the engine in the vehicle that comes from another country and was never legally sold in Switzerland?

Lastly, the comment above about the SAE NET HP ratings started in 1972 and apply to engines installed in a production motor vehicle with all accessories installed/hooked up as well as a full exhaust system on the motor to access the NET HP of the engine.

Gross HP is NOT Net HP...they are very different. Most Crate engines are rated as Gross HP since the higher HP numbers sell more engines but the actual Net HP as installed in a vehicle is usually 10-15% LESS than the gross number. Gross HP is the HP with no accessories hooked up to the engine such as alternator, power steering AC etc, no exhaust system, sometimes open LTH, etc.

The best analogy to Gross versus Net HP is in accounting. If you were to invest in a company with your own money, would you be interested in the Gross revenue (Money coming in with no allowance for the company's expenses) for the operation or the NET revenue (net Income) after all expenses (accessories/exhaust system) were deducted and accounted for? The much more accurate depiction of the company is the NET revenue (income) just like Net HP is MUCH more useful than Gross HP and the reason for the change in ratings system in 1972........

Folks use Gross and Net HP all the time as if there is very little difference between the 2 rating systems. There is a big difference. My 78 L-82 was rated at 220 NET HP in 1978. Using the pre 1972 gross rating's system, the 220 NET HP number would be about 300-310 Gross HP (very close to the 1971 LT-1 330 Gross HP number)!!! See the big discrepancy?

 

I don't know the law in switz but as blue said the parts are basically the same, here in the usa the only thing that's makes a vehicle too modified for on the road is things like bumper height from the pavement, hood scoops that interfere with vision, noise from the exhaust, and super wide.high tires that kick up mud/water to following cars. and to further complicate things what is legal in iowa may not be legal in California, things like window tints and purple dot taillights., but as I said the first part of this post are the most common guidelines. basically anything that does not interfere with the original body shape, height, exhaust sound level, and window tints is considered stock or in the case of a crate motor with headers and intake differing from factory (such as fuel injection etc) is considered semi stock, modified class includes blower poking through the hood, roll cage in the cabin, etc. I would assume that as long as you keep the original body shape and height, and emissions pass your local law, you should be legal.

 

Thanks a lot for all input.

I’ll try to clarify a few things: I’m not actively searching for a car with a crate engine. Also a stock engine is good, and a stock L82 would be ideal. But cost is a limiting factor and what I have seen is that cars with non-original engines typically cost less. And I prefer to not further limit my selection to only original. Living overseas makes the whole search process enough complicated. I cannot just come over to have a look at every potential car. But the worst obstacle is that many private sellers will refuse to make a deal with someone living overseas.

I once imported a used car from another European country into Switzerland, but other than that I have no experience. But I think it works as follows. At the initial inspection for registration each and every detail will be checked. Perhaps they will not check if the engine is original. But more likely they check if the engine number is matching or they will recognize a non-stock engine by other means. At that point I will have to do one of following:

1. Show a document from the engine supplier that certifies that the engine is street legal for that car.
2. Provide the official crate engine spec showing that rated power is less than 20% above stock power, which e.g. would be max 300 HP (net) if the car was once shipped with an L82 engine.
3. Possibly rebuild the engine for lower power and then have it dyno tested at an approved test center to show that power is sufficiently low. This option is too risky and too expensive for me.

Not sure, but I think that if I can prove, with a document, that an otherwise identical car 3 years earlier came with a stock small block engine producing up to 370 HP then that would also be acceptable. And of course the gross/net power ratings have to be considered here as well.

Without the right documents it will be difficult.

 

maybe 1 in 1000 forumn readers will know the import/export laws for swiss, you would be better served by an attorney. as for the actual finding one theres hundreds of car dealerships in the usa that only deal or mainly deal in corvettes, finding a car isn't the issue its the laws to get it to you from what I can tell by your posts, conversely an oem c3 is going to be the same as one with a built engine, the prices will vary from around 10 to 100k depending on year mileage etc. from what your saying im guessing you will be better served retaining counsel in the usa to handle the details and ensure you get what you pay for especially if its sight unseen. basically if someone you hire to broker the sale can purchase and drive the vehicle to shipment port then you know its street legal, but again here in the usa most street legal requirements are based on original body height and dimensions except for exhaust requirements which vary from sate to state, whatever is legal in florida is legal in washington state.
hopefully some member will have first hand knowledge suggestions on dealerships or at least help narrow the search for one, best of luck.

any reputable dealership can provide documentation on whether the engine has been extensively modified or if it is stock.

 

Let this be a lesson to all. Be careful what anti car morons you vote for.
And if I'm investing in a company I want to see both gross and net income a company has to see a better picture of how things run.

 

Here is a little advise and a little opinion on my part.
I looked for a numbers matching corvette when I started to look (original matching engine, trans, rear end, parts and components).
I wanted a 68-72 but what I found in my budget were mostly hacked or "slightly modified" junk.
They looked nice in photos, adds, but in person, the work done needed to be redone.
I came across my 73, it was numbers matching but things like calipers, rotors, water pump, alternator, radiator, ignition and other maintenance items had been changed by the original and prior owner.
The prior owner had all parts and maintenance records for him and original owner regarding what work had been done and receipts for all parts and labor which was very important to me.
Most important, the car was always a California car and I would not consider a car from anywhere but from the western most part of the USA, again my opinion.
Why? we have a very dry environment, which can mean very little or no rust.
I have seen first hand what hack jobs have been done to cars, motorcycles and boats in general when some hack swaps out a motor, trans rear end.
To me the condition of a well maintained corvette that was as close to all original as possible was most important.
When I looked in the interior, it was spotless, well maintained, clean and all original.
Popped the hood, and the engine compartment was clean, original, not re-painted or fluffed up by detailer's and no added chrome goodies.
The paint was redone about 20 years ago in the original white and still looked good. There were a few imperfections in the paint like rock chips and scratches.
Crawled underneath, and found some VP&B upgrades, clean of oil, grime and no fresh paint.
I paid about $2500.00 over what the car was worth on paper, but to me it was worth it.
I've been driving it trouble free for two years and purchasing parts for a body off resto/mod soon.
If it were me, I would considerate on how to the car to Switzerland, then find a nice driver that you can restore and enjoy.
Stay away from dealers who deal in flipping corvettes (buying, detailing, swapping in create motors, painting and selling.

 

So matching block VIN to car VIN just means the block came with the car but it doesn't mean the engine is modified more power.

If a VIN stamp isn't required then any Chevy Small Block or Big Block will work. Now a crate engine is normally a new block not a restored block. So unless your inspector is well versed in Chevy blocks how should they know??

 

Good advice right here
That is exactly what I plan on the 73 I just bought to look like when I'm finished including the color. I found an all original intact California car for $3,500. It has been sitting for 20 years. It will take some work and cash but they are out there.

 

"Street Legal" means different things in different areas- the "legal" part is entirely dependant on what the law states. So what's street legal in california is very different from what it is here in Ontario, Canada, for example. You need the advise of someone who's done this import themselves- not we random forum internet folks.

And then on top of that, buying a C3 is not easy.

The corvette club comment above is probably your best first step. Good luck in your search!

 

Not just Corvettes. Any American older cars imported to Switzerland would have the same hoops to jump through

 

Just have a dyno sheet made.. How many 50 yr old cars still have thier original engines? Not many
GM crates even Edelbrocks are listed for pre 75 cars period as a replacement.

There is no "street legal" wording, only smog legal which most 75 and older (at least in Ca) are exempt from.

 

From a quick internet search it looks like a few corvette clubs in Switzerland. Why not contact them and get the info you need?