2000 6.0l to 2003 4l65e

JeepinMike95 · March 10, 2019

Hello, I’m new to the LS world, but I have a 6.0l from a 2000 Chevy, and I just purchased a 4l65e from a 2003 Chevy Silverado SS which had a 6.0l. Yes I know the 4l80e seems to be the better transmission but I’m putting this driveline in a Jeep and the 80 maybe pushing it for room! Anyways I’m just seeing if the 2000 6.0 will bolt right up to the 03 4l65eor will I have to change some parts ?? Thank you

SierraHD17 · March 10, 2019

No it won't if your engine is a 2000. You have the goofy long crank flange iron head engine that only bolts to the 4L80e auto with no mods. Any newer 6 liter has a spacer on the back of the crank for use with the 80e that can be removed. Once you remove the spacer you can bolt on the 60e style dished flexplate and go nuts.

If you try to do that with your engine you will ram the crank into the torque converter and bury the converter in the pump... destroy it and probably still have a bellhousing gap. If you have the 80e flexplate you should be able to get the 4.3 V6 torque converter from the same era and mate it that way with zero issues. The torque converter in the trans is useless as is.

If your engine isn't actually a 2000 and has the crank spacer you just need the 60e style ls flexplate like the truck you took the transmission from had.

JeepinMike95 · March 10, 2019

Okay, I’ll definitely be checking to see if I have a true 2000 or not tonight ! I did get the flexplate with the transmission so if I DONT have the long crank I should be able to bolt it right up? And if it is the long I need to swap converters and get the original 4l80 flexplate correct ?

SierraHD17 · March 10, 2019

Correct. If it's the long flange you can get a custom converter from anyone that builds them as well.

JeepinMike95 · March 10, 2019

Okay, awesome ! Thank you very much, like I said I’m new to the LS platform, worked with the older SBC like in my Camaro but never the newer so don’t know too much about them and what can go with what!! Thanks again !!!

Gagliano7 · March 15, 2019

Does the engine have iron heads? If so it most definitely has the long crank.

JeepinMike95 · March 15, 2019

It does have iron heads and long crank. I’m going to pick up the original flexplate now to just get the torque converter

Gagliano7 · March 20, 2019

https://help.summitracing.com/app/answers/detail/a_id/4908/~/i-have-an-early-ls-engine-with-a-long-crank.-what-do-i-need-to-bolt-up-my-old

http://www.novak-adapt.com/knowledge/gm-crank-spacing

carkhz316 · March 20, 2019

On 3/10/2019 at 10:49 AM, SierraHD17 said:

No it won't if your engine is a 2000. You have the goofy long crank flange iron head engine that only bolts to the 4L80e auto with no mods. Any newer 6 liter has a spacer on the back of the crank for use with the 80e that can be removed. Once you remove the spacer you can bolt on the 60e style dished flexplate and go nuts.

If you try to do that with your engine you will ram the crank into the torque converter and bury the converter in the pump... destroy it and probably still have a bellhousing gap. If you have the 80e flexplate you should be able to get the 4.3 V6 torque converter from the same era and mate it that way with zero issues. The torque converter in the trans is useless as is.

If your engine isn't actually a 2000 and has the crank spacer you just need the 60e style ls flexplate like the truck you took the transmission from had.

Good info. You should post more in transmission threads. I was about to say that it would bolt up, but realized you're correct about the HD 6.0s having the longer crank.