When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have taken my '70 BB on several 500+ mile roadtrips, so it's definitely possible. I don't know what my rear end ratio is, but it's about 3500rpm at 70. I would love to get a 5-6 speed to drop that down, but I'll still drive it until then. It used to get hotter than normal, but that was with a leaky radiator.
Oh, and I still carry my spare that I keep in the tire rotation. Not that I've needed to use it yet...
I do. I cruise many foothill, mountain and coastal roads where cell service is sparse. If you get a flat without a spare and need a tow, you could be spending some time on the side of the road waiting for assistance or taking a long hike.
I do plan to find a 17" lightweight aluminum wheel and a narrow 27" diameter tire for a spare that will reduce the weight of the steel wheel and OEM style spare tire.
i have a 77 corvette and heard they are not made for long freeway drives, I have also heard they are fine for the freeway. My 77 has a 4 speed transmission, brand new engine, along with new water pump, and new alternator. Are these 77’s with 4 speeds not cut out for 10 hour drives at 75mph? Are they made to cruise at 55mph?
Best mod for long drives? New seats. BIG difference in comfort.
MY age 53, moved from the DC region/Md....to Florida, so all this about trans and ratios depends on your driving requirements.....
In the DC region, the car went from 2nd to 4th all the time, around town.....L48 engine with L98 injection on it.....Muncie and 336 rear which is still in the car 22 year later....
BUT the trips down I95 to Florida.....80 mph all the way, doing 4 grand on the tach.....I got 24 mpg......at FOUR GRAND!!!!
but down here I put an automatic in it some 20 years ago....because stick shifts were costing mega bux.....so have a 200 4r for the 30% drop of engine speed....cruise at ~2400 rpm @80 which is typical highway speed here....
but in fact, the car is parked for many daze at a time, age 73 and so nowhere to go that is much interesting....and that is a LONG story....
I took it out for a while. After blowing a tire in my wife's Porsche in southern Oregon, no cell service, we had to limp about 40 miles on the space saver to the nearest place that had Porsche-sized tires, I decided it might be a good idea to have a spare on board of the Corvette.
Salesmen didn't caution us about long trips when we bought them new back in the 70's. My parents drove mid 50's cars to the beach when I was a kid. My great grand pappy drove a horse and buggy 100 miles. Geez. If your DD can't get you to work, you'd repair it. If your week-ender can't get you 100 miles, you should repair it.
I can't add to the C3 experience (yet) but I think it is all relative. When I take long trips in a 62 TR4 I look at the guys on motorcycles and think, man, what a luxury ride I am in.
LOL! And I look at you from my Harley and think........"All boxed In"! But I compromised and bought a '68 convertible project/wife won't ride the Harley any more. We're looking forward to a "short trip"......Gatlinburg/700 miles one way.
The answer (to me) is quite simple. No spare when driving in my usual area. If I were to take a long trip where I was unsure about cell service I would simply install the spare (and put a floor jack in the back).
If it's in good working order, I wouldn't worry about it. Just inspect it, or get a mechanic to inspect it and make sure suspension, cooling, etc. are in good shape.
I have a non-overdrive 5 speed with 3.08 rear end gears. It does just fine on the interstates.
Drove my 76' to Bowling Green, KY (235 miles, 3.5 hrs) quite a few times for vacation. Made a trip to Road America in Wisconsin (450 miles, 7 hrs), ran two days on the track (spirited driving up to 125mph) , and made it back home in one piece. These cars were meant to be driven.
I've been running mine every year to Carlisle, about 225 miles away, and Myrtle Beach, about 350 miles away and never broken down. I have a 4 speed with 3.70 gears and turn between 3500 and 4000 rpm for hours at a time. Yes, I'd rather have a 5 speed overdrive, but I can buy a lot of gas for that $4000 conversion. As mentioned above, I get about 14mpg. The one time I drove to Carlisle at about 55mph, I got 15mpg. This is on the numbers matching L-82, although it has been rebuilt.
When a question like this comes up, I am always initially dumbfounded by it. Our C3 cars were built in a time when automobiles travelled anywhere and distance was never an issue. The fact that forty years have went by does not change that in any way. Of course, its a mechanical object that needs to be maintained properly, but if it is, there is no reason you couldn't drive from DC to San Francisco. I would do it tomorrow if I had time.
As for comfort, I could sit in my stock 77 seats for 12 hours without discomfort, and in fact are more comfortable than my wife's Camry or the 2015 GMC Canyon I bought, and then sold (strictly because how uncomfortable the seat were past 45 minutes of driving).
As for cruise RPM, its a bit shocking when you first put it in 4th gear and get up to speed and look at the tach.....I am normally looking for another gear. At 55 mph my 3:55 differential and factory Borg T-10 four speed puts me around n 2800 RPM, and while it seems like a high number, simple solution......just stop looking at the tach and stop worrying about it. Gas mileage is irrelevant, but I get between 15-17 mpg.
Lastly, I will never understand modern people, or people driving C3 Corvettes. Why is it necessary to go everywhere at 70 plus MPH? In Pennsylania, with the exception of major feeders into cities, and the turnpike, the speed limit is 55 mph everywhere else, and frankly, there is no need to go faster than that. So the solution to peoples concerns of high RPM is simple.....SLOW DOWN!!! Enjoy yourself, look around, and the car will provide all the reliability and safety anyone needs. I drive 5000-6000 miles a year on my 77, and do it mostly at 55 mph or less. You can make fun of me, but frankly, I don't really know why everyone is in such a rush??? Is it only fun going 70 mph? I DO like getting up to cruise speed quickly i.e. acceleration offers more fun factor than just sustained high speeds.
Last edited by Torqued Off; 01-21-2018 at 08:28 AM.
My 73 BB TH-400 with 3.36 rear gears runs at 3070 rpm @ 70 mph on the highway. The rpm is a little high for my liking for drives over 30 minutes, so I have a tendency to cruise in the slow lane at 60-65 on the highway of longer drives. Kind of embarrassing being America's sports car.
My 71' BB, T400 car also has 3.36 gears, and turns 3k @ 70 mph, I've driven it cross country twice in the last 3 years, running 70-75 mph....It'll be fine...
11.8 mpg @ 3k rpms
Get em out there and drive em people! They are cars, they'll be fine.
Why is it necessary to go everywhere at 70 plus MPH?
In a lot of states the interstate speed limit is 70 mph. If you're going below 65 mph around here you will get ran over. If you want to run only 55 mph you had better be on one of the old highways like US40, US31, etc.
I personally like the old state roads for road trips, much more interesting scenery. However, if I'm going to say Bowling Green, I usually take the interstate that puts me near or over 70 mph to flow with the traffic. Most people now days get really irritated with someone going 15 mph below the speed limit on the interstate.
Not everywhere is like Pennsylvania. In Tennessee it is actually illegal to drive under 55mph on a highway or interstate that is part of the state system. My point is that speeds vary all over the US, and some don't have the option of running below 55 mph if you're travelling on the interstates.
I do have a new spare tire, just in case the flat tire is ruined, will try to call someone to change it though, the jack in these cars is a "only if have to " type in my book.
In a lot of states the interstate speed limit is 70 mph. If you're going below 65 mph around here you will get ran over. If you want to run only 55 mph you had better be on one of the old highways like US40, US31, etc.
I personally like the old state roads for road trips, much more interesting scenery. However, if I'm going to say Bowling Green, I usually take the interstate that puts me near or over 70 mph to flow with the traffic. Most people now days get really irritated with someone going 15 mph below the speed limit on the interstate.
Not everywhere is like Pennsylvania. In Tennessee it is actually illegal to drive under 55mph on a highway or interstate that is part of the state system. My point is that speeds vary all over the US, and some don't have the option of running below 55 mph if you're travelling on the interstates.
Yep, and our interstate speed limit in Texas is 80 mph. I can't even keep up on the interstate...
Coming back from the HR Power Tour last summer, running down I10, I was running 75 mph and 18 wheelers were blowing passed me like I was sitting still, all while honking and blowing the horn at me... Moms in minivans were passing me and flipping me off...lol.. At that point, I realized that I REALLY need over drive for cross country trips, just to survive and not get ran over...
I have little interest in interstate driving. First of all, it extremely boring. If I went to California from Pennsylvania, it would be on back roads. Its same on my Harley....no interest in interstate....that's not where the fun is. If you have to go somewhere fast, you should fly the airlines. So, I am lucky, my style of driving fits perfectly with a classic C3 Corvette.
You people do realize the carnage going on everywhere on interstate highways.....try this next time you are driving, start watching for skid marks crossing the roads, paint marks on barriers, and burn marks from fires. When you start looking for them, you will see them everywhere. We have come to the place in America that driving cars 80-100 mph on highways is commonplace,.....that by no means says that it is safe to do so, and the horrific accidents occurring all the time are a result of it. Until you experience it yourself, or witness, you all can remain naïve.
Our C3 Corvettes are way behind when it comes to safety, and I for one am avoiding interstates and turnpikes, and minivans with moms......because none of them have any clue of the carnage right awaiting them.....until there precious little child is crushed because they thing they are Jeff Gordon.
Last edited by Torqued Off; 01-21-2018 at 10:52 AM.
As a kid I took my 67 400 cu 4 speed Firebird all over including 600 mile trips with a 3:55 rear. I had no issues.
I take my 1980 Chevy Truck with 3:55 rear and automatic all over, 8 and 10 hour trips with no issues and have since 8/29/79 when I purchased it new.
My 71 has a 5 speed and I cruse all over, thinking nothing of long trips.
The key is PREVENTIVE MAINTENANCE and frequent oil changes. Run a good quality oil, put in a bottle of ZEDD and have a great trip.
That is what I do ... no issues and 480K miles on the truck - original engine second trans, rebuilt rear. This summer will be the 15th set of tires and just put in the 4th set of seats.
I drive my 76 at 70 all the time on Interstates, and have no problem, like to St Louis(4 hours, or Kc, 3.4 hours) with no problem. This a stock 76 motor and transmission. The worst part is the seats, as you get older, your other car's seats are more comfortable.
The 79 and later seats are much more comfortable. I wouldn't be concerned about a 10 hour drive in my 79. I tried out the earlier seats and to me I think they'd be a problem after a couple of hours.
01-19-2018, 12:03 PM
, and made it back home in one piece. These cars were meant to be driven. 
