rear end

[Ron Fegley]

Hi, Im restoring my 73 vette. I have a 454 engine with a 1967 4.11 rear end. I would like to cruise at 65 with about 3500 rpm. What ring gear should I use for this rear end? Where can I get it economically?

Thanks, Ron

[John H.]

Re: rear end

Ron -

With 27.4" tires (G70-15 or 225/70-15), 3500rpm at 65mph calculates to a 4.39 ratio (which doesn't exist) - with your 4.11, you should be seeing about 3280rpm at 65 mph as your car sits right now. The next ratio step up is a 4.56, which would give you about 3630rpm at 65mph. Hope you don't do much highway cruising

[John H.]

Re: rear end

Ron -

With 27.4" tires (G70-15 or 225/70-15), 3500rpm at 65mph calculates to a 4.39 ratio (which doesn't exist) - with your 4.11, you should be seeing about 3280rpm at 65 mph as your car sits right now. The next ratio step up is a 4.56, which would give you about 3630rpm at 65mph. Hope you don't do much highway cruising

[Ed Jennings]

Re: rear end

My 67 has a 3.70, and it turns about 3100 or so at 65. My 62 has a 3.55 which turns about 2800 at the same speed. That might give some idea of the relative ratios. The only BB I ever owned was a 71 that had a 3.08. It had plenty of low end even with the 3.08. You might want to consider a 3.55 or a 3.36 and really get the RPM's down to a reasonable level at highway speed. I'm no diffeential expert, but I think you would have to change more than the ring and pinion to get to the gearsets below 3.70.

[Ed Jennings]

Re: rear end

My 67 has a 3.70, and it turns about 3100 or so at 65. My 62 has a 3.55 which turns about 2800 at the same speed. That might give some idea of the relative ratios. The only BB I ever owned was a 71 that had a 3.08. It had plenty of low end even with the 3.08. You might want to consider a 3.55 or a 3.36 and really get the RPM's down to a reasonable level at highway speed. I'm no diffeential expert, but I think you would have to change more than the ring and pinion to get to the gearsets below 3.70.

[Joe L.]

Re: rear end

Ron-----

I don't quite understand what you mean by "what ring gear you should use"? Ring and pinion gears are always interchanged as SETS, even if the ratio is not changed. You cannot create a non-original gear ratio by simply changing the ring gear with an existing pinion gear installed. The gears must always be changed as SETS only. No individual gears are/were even available from GM or anyone else.

All 63-82 Corvette ring and pinion gear sets are GM-discontinued. Aftermarket gear sets are manufactured by Richmond Gear and U.S. Gear. Either are available from Tom's Differentials of Paramount, CA. Many of the Corvette vendors carry the Richmond Gear-manufactured gears. I recommend the U.S. Gear product, though.

Available ratios include 2.73:1, 3.08:1, 3.36:1, 3.70:1, 4.11:1, 4.56:1, and 4.88:1.

[Joe L.]

Re: rear end

Ron-----

I don't quite understand what you mean by "what ring gear you should use"? Ring and pinion gears are always interchanged as SETS, even if the ratio is not changed. You cannot create a non-original gear ratio by simply changing the ring gear with an existing pinion gear installed. The gears must always be changed as SETS only. No individual gears are/were even available from GM or anyone else.

All 63-82 Corvette ring and pinion gear sets are GM-discontinued. Aftermarket gear sets are manufactured by Richmond Gear and U.S. Gear. Either are available from Tom's Differentials of Paramount, CA. Many of the Corvette vendors carry the Richmond Gear-manufactured gears. I recommend the U.S. Gear product, though.

Available ratios include 2.73:1, 3.08:1, 3.36:1, 3.70:1, 4.11:1, 4.56:1, and 4.88:1.

[Gary S.]

Re: rear end

Ron, if you want to play around with the gear ratios on a computer to see how the variables change, try the following web site: http://www.idavette.net/tech/ratioc.htm

Secondly, my 72 LT1 with 4.11's, 26" tires and everything else stock, turns 3450 rpm at 65 mph. That really is a lot of rpm. You can see what happens, using the rear end ratio calculator, when you change either the speed, rpm, or tire size with that gear set.
Gary

[Gary S.]

Re: rear end

Ron, if you want to play around with the gear ratios on a computer to see how the variables change, try the following web site: http://www.idavette.net/tech/ratioc.htm

Secondly, my 72 LT1 with 4.11's, 26" tires and everything else stock, turns 3450 rpm at 65 mph. That really is a lot of rpm. You can see what happens, using the rear end ratio calculator, when you change either the speed, rpm, or tire size with that gear set.
Gary

[Jack layton #896]

Re: rear end

I own a 1965 396/425 with the 4.11 rear. This is not a great combination.
Unless you only travel 1 block at a time. The engine blasts through it's power curve so fast that there is no time to actualy use all the power. Then if you want to travel any distance you have to listen to the motor wind itself crazy while you maintain 65-70 mph. A 3.08 or 3.36 is a far better choice.
What are your intentions for this car that make you feel you need a 4.11 behind a 454 ? That thing will melt the rear tires in third gear. From a guy who owns one of these monsters let me suggest you reconsider your position. IMHO

[Jack layton #896]

Re: rear end

I own a 1965 396/425 with the 4.11 rear. This is not a great combination.
Unless you only travel 1 block at a time. The engine blasts through it's power curve so fast that there is no time to actualy use all the power. Then if you want to travel any distance you have to listen to the motor wind itself crazy while you maintain 65-70 mph. A 3.08 or 3.36 is a far better choice.
What are your intentions for this car that make you feel you need a 4.11 behind a 454 ? That thing will melt the rear tires in third gear. From a guy who owns one of these monsters let me suggest you reconsider your position. IMHO

[Patrick T.]

4:88 rear end

I had a midyear long time ago, with a 3:08, but I wanted some more punch, so I put in a 4:88. As I remember, I was doing 4000 RPM at about 55 MPH. That rear lasted about a month or so before I changed it back.

[Patrick T.]

4:88 rear end

I had a midyear long time ago, with a 3:08, but I wanted some more punch, so I put in a 4:88. As I remember, I was doing 4000 RPM at about 55 MPH. That rear lasted about a month or so before I changed it back.

[Ron Fegley]

Re: rear end

Thank you friends. The car came with a 4.11. I thought 3500 might be a nice cruise rpm, but you have made me see the error of my ways. I think I will take your advice for a 3.08, and you have given me a good source for gears. Thanks also for the handy calculator.

Thanks again.

Ron

[Ron Fegley]

Re: rear end

Thank you friends. The car came with a 4.11. I thought 3500 might be a nice cruise rpm, but you have made me see the error of my ways. I think I will take your advice for a 3.08, and you have given me a good source for gears. Thanks also for the handy calculator.

Thanks again.

Ron