Why a 4:11 in an L84?

[Charles P.]

I have been looking to buy a 65 fuelie for several years but I have noticed that many of the cars I have come across have the 4:11 posi (which was custom ordered). I was wondering what the logic was for a 4:11 in a L84? The 4:11 backend runs out of "go" pretty quickly in 4th gear.

You don't see nearly as many 4:11 in the 365 or 350 cars. I always thought a 4:11 was mainly for people who lived in mountainous areas.

Dosen't the L84 have less low-end torque compared to the 300 or 350 engines? If, back in the day, you wanted a fast off the line car, why wouldn't you order a 300 or 350 car with a 3:70 over the L84 with a 4:11? If you were intending to race the car, wouldn't you want a lower backend to take advantage of the higher RPMs and provide more high-end 4th gear speed?


I would be interested in the logic.

[Jim L.]

Re: Why a 4:11 in an L84?

The simplest answer is that the 4.11 differential got you 0-60 bragging rights.

[Alan D.]

Re: Why a 4:11 in an L84?

And helped at the 1/4 mile track

[Steven B.]

Re: Why a 4:11 in an L84?

The simplest answer is that the 4.11 differential got you 0-60 bragging rights.

What Jim said. Back in the day acceleration was king. We ran the 1320 outside of town often. Many guys who ordered new performance machines ordered 3.70's or more (4.11 or 4.56). I went with a friend to pick up his new '68 Z-28 and it beat a new 440 RT TorqueFlite. He was the new guy to beat and bragging rights prevailed. Not many top end runs or 100 mph stomp downs in our area, just 1320 runs so rears in the 4's. Much more fun than searching on my laptop.

[Duke W.]

Re: Why a 4:11 in an L84?

Back when these cars were new there were no interstate highways to speak of, but we knew they were coming and would, by design, allow safe 80 MPH cruising though most states set lower limits as they were built.

New Corvettes back then were daily drivers, so good acceleration was was at a premium and top speed was not an issue. Typical two lane US and state highway speed limits were 55 MPH.

Chevrolet offered six axle ratios with the mechanical iifter C2s from 4.56 to 3.08. Standard was 3.70, but dealer and customer orders were often 4.11, which was "the thing" back then. If your hot rod Chevy didn't have a "4.11" other car guys though you were a moron.

Being a contrarian, I ordered my 340 HP SWC with a 3.08. Most thought I was crazy, but I was looking ahead. I wasn't interested in drag racing. Road racing was my passion and I wanted gearing for top speed, which I got having achieved 150+ MPH a couple of times and cruising on deserted new freeways in the late sixties at 130 MPH and even 100 MPH in the rain on a fresh set of Pirelli Cinturato CN 72 radial tires.

The 3.08 took some getting used to, especially in hilly Seattle were we spent our first five years. I always referred to the 3.08 as like a five speed with no first gear and the 4.11 as like a five speed with no fifth gear, and I always thought it was cool that back then I could break every speed limit in the country in FIRST gear, which yielded about 76 MPH at the 6500 redline.

I avoided "stop light grand prixs", but always looked for victims on open roads with a rolling start from about 40 (I'd be in first gear). If there was enough open road in front of me there was no way I could loose because there was no "muscle car' on the planet that had the gearing if not the power to to get one of those bricks up to 150.

Duke

[Terry M.]

Re: Why a 4:11 in an L84?

Charles,

I'm the owner of one of the 771 copies built for 1965. Rear end (original) with AQ stamp (4.56). Car sat since early '80s and was in a dirt floor garage just prior to when I bought it. Odometer read 17,500 which, I assume to be original miles. After all, who could put 117,500 miles on a fuelie Vette with a 4.56 rear gear. I am convinced the car was originally purchased for one purpose only....1320 spurts and/or stoplight "testing". The car is otherwise nicely optioned with AM/FM, Comfort and convenience group, tinted glass and off road exhaust. Also a hubcap car. The '65 fuelies are great cars and a great investment. If you can't stand the 4:11s and want to drive the car a lot, swap in a 5-speed and get the best of both worlds. A 5-speed with a 0.85:1 fifth gear will reduce your final drive to 3.49:1 (4.11x.85=3.49). If you can find a '65 fuelie for the right money it shouldn't matter what the gear is in my opinion.

[Mel S.]

Re: Why a 4:11 in an L84?

And remember gas was less than a dollar a gallon. And YES, 4:11 or 4:56 was the way to go. I even put in a set of 4:88 before a race and won. The good old days.

[Michael J.]

Re: Why a 4:11 in an L84?

My '63 Z06 has 4.56, and I would have no other gear in it. The L84 needs to be in the high RPM range to get into its peak power band, and the 4.56 is great, a 4.11 would be too.

[Steven B.]

Re: Why a 4:11 in an L84?

And remember gas was less than a dollar a gallon. And YES, 4:11 or 4:56 was the way to go. I even put in a set of 4:88 before a race and won. The good old days.

The days of lower gas prices and lower wages. I worked in a Mobil station in the 65 time frame and remember prices in the $0.25-$0.30 range. One Saturday evening the Marathon station kept cutting prices so I called my boss multiple times for a penny cut. Finally Roger said go to $0.199 and if he goes lower close up. He went lower.

[Tim G.]

Re: Why a 4:11 in an L84?

So many good memories. My first Corvette was a 1969 350 horse with 4.11. It was 320 miles from Chicago to Eau Claire, WI where I went to school and that motor ran at 4500 RPM all the way to and from. I didn't know any better and it didn't bother me at all. I can't imagine running a motor for six hours each way today at that RPM for that long.

[Michael J.]

Re: Why a 4:11 in an L84?

Yes, how quickly we forget that a car with a high performance engine, like an L84, is meant to be driven and the RPM is what you need to hear and feel, and not be afraid of. I agree with Carroll Shelby, who famously said: "There's a point at 7,000 RPM... where everything fades. The machine becomes weightless. Just disappears. And all that's left is a body moving through space and time. 7,000 RPM. That's where you meet it. You feel it coming. It creeps up on you, close in your ear. Asks you a question. The only question that matters. Who are you?"

[Bill M.]

Re: Why a 4:11 in an L84?

Mike you hit the nail on the head. How many of these cars are dying to get out o the road and really blast out a run ? A shame most of them barely drive out of the trailer.

[Chris H.]

Re: Why a 4:11 in an L84?

Love the 4.11s in my ‘69 L71. It’s a back road beast and never sees the interstate. Also pretty sure part of the reason it only had 14k miles when I purchase in 2011. With those gears it always ready to go.

[Mark E.]

Re: Why a 4:11 in an L84?

For drag racing, the idea is to select gearing so the engine is in its peak power band as it goes through the traps. For most vintage high-perf Corvettes, this means hitting red line around 95-115 mph. For example, with 4.11 gears, 6,000 rpm is about 117 mph.

[George H.]

Sales Invoice 1964 Corvette.jpg