LY6 and 4l80e question
Thread Starter
Teching In
Joined: Mar 2024
Posts: 31
Likes: 7
From: Selah, WA
LY6 and 4l80e question I have a built LY6 engine that I’m getting ready to install in my project.
I also have a built 4l80e trans with billet converter. I bought a TCI Flexplate part number 399754. The flexplate comes with an extension/adapter for the crank. Do I need to use this extension/adapter or is that for older transmissions and or dished flexplates?
I also have a built 4l80e trans with billet converter. I bought a TCI Flexplate part number 399754. The flexplate comes with an extension/adapter for the crank. Do I need to use this extension/adapter or is that for older transmissions and or dished flexplates?
TECH Apprentice
Joined: Aug 2018
Posts: 380
Likes: 107
I couldn't get the photo to show up on my Summit Racing app on my phone, but looks like that's specifically designed for the LS engines:
description:
"Flexplate to crank bolts and pilot hub adapter included. This flexplate is designed for use when bolting a GM LS-based motor to a 4L80E and utilizes the 6-bolt mounting pattern. This flexplate is drilled with a 11.50 in. bolt pattern. Since the crank spacer is built in, this will not fit 1999-2000 6.0L applications with 0.400 in. extended crank flange and came with flat flexplate. This will not fit 1999-2000 4.8L applications that originally came with a manual transmission."
Edit: so yes, use the adapter/spacer that was included. They only exception for leaving out the spacer is if you were to have those super early 99-00 engines with the long crank, but you don't.
description:
"Flexplate to crank bolts and pilot hub adapter included. This flexplate is designed for use when bolting a GM LS-based motor to a 4L80E and utilizes the 6-bolt mounting pattern. This flexplate is drilled with a 11.50 in. bolt pattern. Since the crank spacer is built in, this will not fit 1999-2000 6.0L applications with 0.400 in. extended crank flange and came with flat flexplate. This will not fit 1999-2000 4.8L applications that originally came with a manual transmission."
Edit: so yes, use the adapter/spacer that was included. They only exception for leaving out the spacer is if you were to have those super early 99-00 engines with the long crank, but you don't.