The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 2001-2002 Allison vs 4L80E in a K2500

**jocko** · 09-14-2018, 11:13 PM

Quick question - I'm a 4L80E fan, but have no experience with an Allison 5-speed. While I'm assuming the optional Allison has a higher torque rating, the 4L80E is no slouch. Am mostly concerned with longevity. Interested in your thoughts for those that have had both or either. My puny 4L60E in my 1/2 ton is on its third life. Am looking around at 01-02 2500HDs and am curious about teh Allisons - am finding more for sale than I thought I would.

And does anyone know the Allison gear ratios handy?

Also, I "thought" they were only available from the factory behind a big block or a diesel, but I have seen some listed on 6.0L trucks that are for sale. Was that an option?

09-14-2018, 11:13 PM	#1
jocko Senior Member Join Date: Oct 2009 Location: Godley, TX Posts: 17,934	2001-2002 Allison vs 4L80E in a K2500 Quick question - I'm a 4L80E fan, but have no experience with an Allison 5-speed. While I'm assuming the optional Allison has a higher torque rating, the 4L80E is no slouch. Am mostly concerned with longevity. Interested in your thoughts for those that have had both or either. My puny 4L60E in my 1/2 ton is on its third life. Am looking around at 01-02 2500HDs and am curious about teh Allisons - am finding more for sale than I thought I would. And does anyone know the Allison gear ratios handy? Also, I "thought" they were only available from the factory behind a big block or a diesel, but I have seen some listed on 6.0L trucks that are for sale. Was that an option?