4L60E w/ 2.41 rear

[Texas82GP]

The purpose of an overdrive trans is that you can run numerically higher gear ratios. Hence why the 2020 C8 Corvette has a 5.11 gear in the back with its 8-speed transmission. With a 4L60E trans, I would run a minimum 3.73 or higher gear ratio. A 4.10 would be ideal. This will give the vehicle better acceleration due to torque multiplication. It is also easier on the drive train as it puts less stress on the engine & trans.

GM installed 3.73 gears in G-Body Olds 442's with the 2004R. This helped the anemic 5.0 engine with its pathetic 200HP to at least accelerate fast enough to get out of its own way and merge onto highways without getting killed. In OD the 2004R with a 0.67 ratio turned that 3.73 gear into a 2.49 ratio when in OD so you still get great highway cruising RPMs

A 2.41 gear with an OD trans will make the vehicle accelerate like a turd.

Possibly slower than a turd.

 

[1evilregal]

The purpose of an overdrive trans is that you can run numerically higher gear ratios. Hence why the 2020 C8 Corvette has a 5.11 gear in the back with its 8-speed transmission. With a 4L60E trans, I would run a minimum 3.73 or higher gear ratio. A 4.10 would be ideal. This will give the vehicle better acceleration due to torque multiplication. It is also easier on the drive train as it puts less stress on the engine & trans.

GM installed 3.73 gears in G-Body Olds 442's with the 2004R. This helped the anemic 5.0 engine with its pathetic 200HP to at least accelerate fast enough to get out of its own way and merge onto highways without getting killed. In OD the 2004R with a 0.67 ratio turned that 3.73 gear into a 2.49 ratio when in OD so you still get great highway cruising RPMs

A 2.41 gear with an OD trans will make the vehicle accelerate like a turd.

Possibly slower than a turd.

wonderful.... just as I'm getting ready to hook up a 4.3 vortec/4l60 in the wagon with what is probably the same gears.... whoever comes out first lets the other know the deal....

 

[Texas82GP]

wonderful.... just as I'm getting ready to hook up a 4.3 vortec/4l60 in the wagon with what is probably the same gears.... whoever comes out first lets the other know the deal....

I mean, it will run and drive. It's just far, far, far from ideal. My best friend had an 85 Delta 88 with a 307, 200-4R and a 2.41 rear. It was great on the highway. It was a slug through the gears. It was typical of cars of that time. It ran about the same as my Mom's 86 Buick Century with a carb'd 2.8 V-6 with the A/C running.

 

[Texas82GP]

wonderful.... just as I'm getting ready to hook up a 4.3 vortec/4l60 in the wagon with what is probably the same gears.... whoever comes out first lets the other know the deal....

Can't you swap the gear set out of the donor Blazer?

 

[Tomeal]

wonderful.... just as I'm getting ready to hook up a 4.3 vortec/4l60 in the wagon with what is probably the same gears.... whoever comes out first lets the other know the deal....

You'll beat me to the answer! I'm asking these questions to formulate a plan to figure out what direction to go.

 

[64nailhead]

If you plan to stay with a stock 14" tire, then leave the 4L60E behind (especially if you plan to upgrade to an LS later), use the TH350 and be a smiling 3 speed owner.

Keep in mind, that the 4.3 is turd no matter what's behind it, so IMO attempting to make that more driveable is a fruitless option. When the LS goes in, install a mild cam with headers and it won't care if you have a TH350 behind it. And lastly, you let someone else grenade the 4L60E. The 4L60E is almost underrated for a stock 5.3 - any hop up in a 5.3 or a stock 6.0 and the 4L60 will be found in smaller pieces than originally installed.

 

[Texas82GP]

If you plan to stay with a stock 14" tire, then leave the 4L60E behind (especially if you plan to upgrade to an LS later), use the TH350 and be a smiling 3 speed owner.

Keep in mind, that the 4.3 is turd no matter what's behind it, so IMO attempting to make that more driveable is a fruitless option. When the LS goes in, install a mild cam with headers and it won't care if you have a TH350 behind it. And lastly, you let someone else grenade the 4L60E. The 4L60E is almost underrated for a stock 5.3 - any hop up in a 5.3 or a stock 6.0 and the 4L60 will be found in smaller pieces than originally installed.

Totally agree. See my thread for my 4L80E swap when I finally smartened up and quit spending money on the 4L65E in my truck. The 4L60E is marginal for stock use, in my view.

Texas82GP's GMT900

A little less than two weeks ago the transmission went out on my daily driver. It's a 2008 GMC Sierra 1500, regular cab, short bed, two-wheel drive with a 5.3 and a 4L65E transmission. The 4L65E has been built twice in the last 50k miles. It has some nice goodies inside it but I keep finding...

gbodyforum.com

 

[1evilregal]

Aren’t the axle splines a different count, and axle shafts different lengths?

 

[Tomeal]

Aren’t the axle splines a different count, and axle shafts different lengths?

If I switched to the 4L60E, I would have to have the driveshaft shortened. I wouldn't if I kept the 200/350.

 

[1evilregal]

If I switched to the 4L60E, I would have to have the driveshaft shortened. I wouldn't if I kept the 200/350.

Correct, what Jared was referring to was that I have the entire 2wd blazer that’s giving up the engine and trans (among other parts), and was suggesting using the gears as well....