I was thinking about putting a 4.11 rear end gear in my camaro and i know this is a dumb question but i dont know what the whole spline thing is and also anyone that has a 4.11 what rpms are u runnin just cruisin around at like 55

All depends on the dia. of your rear tires. With a non overdrive trans and 4.11 gears with 26" tall tires you will be just over 2900 rpm @ 55 mph.

I have a powerglide so it will probally b screaming

i'm not totally sure but I think the final gear ratio of a P.G. is 1.1 and if i'm right those calculations I gave you earlier will be where your at. What gear do you have in it now?

Its stock and i ant sure i belive its a 2.somethin or 3.00 but ive been trying to decide between a 3.73 and a 4.11 but i believe i will go with the 4.11

where are you driving this car all the time. to race track and some shows go with 411. if you driving it for around town and to shows and high ways for cruising ill go with 373 or a 355.

The "spline thing" is how many splines are cut into the axle where it fits into the differential. Stock is 28. Not a factor with a gear change, unless you are also buying a new differential.

There is also the "series thing."
Differnetials are manufactured to fit "2 series", "3 series", and "4 series gears."
This is because as the gear ratio is changed, the pinion gear changes in diameter, so the ring gear has to move sideways in the car to mesh to the pinion properly.

Bottom line: if your gear now is 2.73 or less, you will have to change the differential to change gearing.
If it is 3.08 or more, you can put in a 3.73.
"Thick" 4.11 gears are also made that will fit, but a standard 4.11 gearset won't, so make sure you order the right one.

And 10 and 12-bolts too!

10-bolt, 4.11 and 12-bolt 4.10!

And imho, the BEST two reg's GM made are the old 12-bolt, 3.31 and 10-bolt, 3.36!

These gears will allow tire turning if you have any power at all as well as you can run down the hwy at 70 mph at something like 3050 rpm w/ a 25.5" tall STOCK sized tire!

He, He!! 82 mph at 3050 rpm w/ a 29.5" tall M&S's on her and just ask me how I know.

And fwiw, my 350SS, M-20 car came stock w/ 3.31's b/c I didn't check any boxes so GM musta though they were dead-nuts-on!

pdq67

If its not a race car swap the glide for a TH350 and some 3.55 or so gears alot more street friendly.

i have 4.11's in my car,it's been off the road for a while, but it still has the same tires on it. they are p275/60r15, at 60mph she used to tach about 3500 rpm, with a turbo 350 trany, but i have seen this very with different cars.but this it is not gospel!

Its not a race car or anything i drive it to school every day and i dont want to change the powerglide cause its still a numbers matching car. But i do want to get a 3.73 or a 4.11. And if i did i would have to change the differential? And also how exactly do i know what the gear ratio thats in it now is

I have a Powerglide and also 4.10's. ALL trannies with a 1:1 final drive ratio will give you the same running rpm. Now, an overdrive tranny has a .64:1 final drive ratio(as an example) so whether you have a Powerglide, TH-350 or a TH-400 you are going to get the same running rpm provided you have the same tire diameter. I have a 24.5" tire diameter and I run at 3098rpm @55mph.

I have a Powerglide and also 4.10's. ALL trannies with a 1:1 final drive ratio will give you the same running rpm. Now, an overdrive tranny has a .64:1 final drive ratio(as an example) so whether you have a Powerglide, TH-350 or a TH-400 you are going to get the same running rpm provided you have the same tire diameter. I have a 24.5" tire diameter and I run at 3098rpm @55mph.

You will get the same running RPM but the 3 speed trans gives you better acceleration with a taller gear due to the lower gear ratio in the trans. A TH350 with 3.55 rear gear would be equal to a PG with a 4.40 rear gear in first gear.This way you would be turning about 800 rpms less at 60 and still have the acceleration you want.As for the numbers matching just store the original trans. thats what I did.

I may decide to get a turbo 350. Is it true that the powerglide dont give u as much power from a dead stop??????

I may decide to get a turbo 350. Is it true that the powerglide dont give u as much power from a dead stop??????

Its not that you dont have the power its all about gear ratios.To get the overall ratio in a certain gear you multiply the trans. ratio in that gear by the rear axle ratio.

TH350
1st gear 2.52x3.55=8.946
2nd gear 1.52x3.55=5.963
3rd gear 1x3.55=3.55

If you take the 8.94 total ratio from the TH350 and 3.55 rear and divide it by 1.76 the 1st gear ratio from the glide you get 5.08.You would need 5.08 rear and a glide to equal a TH350 with 3.55 gears.

More food for thought 3.08 rear x 2.52 = 7.76 4.11 rear x 1.76 glide 1 gear = 7.23
You can run 3.08 rear with a TH350 and have almost the same ratio as the glide with 4.11s
25" tire with 3.08 = 2484 rpms at 60 mph
25" tire with 4.11 = 3314 rpms at 60 mph
http://richmondgear.com/101032.html

And thats just the 1st gear advantage adding the 2nd gear makes it even better.

So if i got a turbo 350 i really wouldnt need that low of gear if i stuck with the power glide????

Thanks for all ur help

So if i got a turbo 350 i really wouldnt need that low of gear if i stuck with the power glide????
No where as low of a gear as with the PG.You may not even need to change gears alot of cars came with 3.08s.

Is their anyway to know what the cars came with????

The gear code is stamped on the front side of the axle tube on the passenger side about 3" over from the center housing.At the bottom of the index page their is a link to 67 68 69 info with gear ratios listed.
http://www.camaros.org/drivetrain.shtml#RearAxleNumbers

Its a little gunky so i couldnt really tell but about how much will a turbo 350 cost

Most local shops will build one for $500.00 to $800.00 maybe less but not more.They are an easy trans. to build.

well my dad has been trying to talk me into a turbo 350 but ive heard good and bad things about powerglides but i believe i will change into a turbo 350 and if i do i will se how it is with the rear end gear in it

Good idea let us know how you like it.

I will thanks for all the help