ok guys, someone has to know for sure, the 100% truth on this.. Heres the deal, i have a 1999 silverado extended cab shortbed 4x4 with the 4.8 engine and 4l60e trans, all original. I want to swap in a 6.0 and keep my 4l60e and stock torque convertor and all, will beef up the trans to hold up to the 6.0.
Ok, From what i have heard, in order to use my stock convertor and 4l60e, i need to find a 2001-up 6.0 to avoid the oddball longer crankshaft. ok, that would be no problem, but i read somewhere yesterday it needed to be a 2004-up to avoid the oddball longer crank, so back to the drawing board.. Does anyone know the truth? I know an LQ9 would bolt right up seeing as they were mated to 4l65e and 4l70e, but most likely it would be an lq4 that was mated to a 4l80e that i would use being as they are cheaper, but, will the lq4 work, even if it is newer than 2001 or will it STILL have the longer crank? I am looking at a 2004 lq4 out of a savanna van and another 2003 lq4 from a 2500 truck, will they work or will they have the dreaded longer crank? I dont wanna mess with having a custom convertor made or any of that, i just want to pull out the 4.8 and install the 6.0 and be done.. anyone know the truth? If all year lq4's will be a problem with the longer crank, i guess ill have to save longer for the lq9, need to know the truth before i buy anything..This is already being done on a tight budget and i sure dont want to order an engine and it not work without custom convertors and all.
Thanks

 

I am pretty sure you are correct in that only the 99-00 had the spacer built on the crank... if you get a later one then it will have the removable spacer and a "flat flywheel" used for 4l80e's. So just reuse your 5.3 "concaved" flywheel on your 6.0 without the spacer and you will be good to go.

 

IIRC another sanity check would be the iron headed engines (99-00) had the longer crank. You also need to make sure it has a 24x reluctor (01-06) or else you will need a crank signal converter.

 

ok, so for sure i am safe with a 2001-06, even if it is an lq4 that came with a 4l80e originally, it will have a removeable spacer on it, no exceptions? Just wanna be sure because i dont want to order one and it arrive and have the longer crank and then i cant use it. Like i said, it wouldnt be a worry if i get a lq9, but it will probably be an lq4 from a 2500 truck or van..
again, so for sure 2001-06 wont have a longer crank, just the removeable spacer?
Thanks!

 

Correct.. like bigkid mentioned.. ive never seen one later than a 00 with iron heads that the crank was longer. Ive seen alot lq4s and every one from 01 up had a spacer between the flywheel and crank. The spacer is to move the flywheel out further for the 80e.. but you will just use your oe flywheel. I would keep that flywheel and spacer in case you ever go 80e lol..

 

awesome, thanks! Only other question now is, i have also heard that 1999-2000 4.8's also had the oddball longer crank, if this is true, im screwed because mine is a 1999 with the 4.8...

 

Not 100% on that. .but seeing alot of 4.8 vans had 4l80e transmissions it does seem very plausible that the van 4.8s could.

 

My dad's 2000 4.8 did NOT have the longer crank. We swapped it out for an LS1 and it bolted up to the 4L60 just fine. I would think yours does not have the longer crank as I have only heard of the 6.0 engines in the trucks having the longer crank.

 

You have nothing to worry about.

The Longer crank 4.8's were only used on the manual transmission and the 4L80E in 99-00. They were NOT used with the 4L60E.

The 6.0L from 99-00 had Iron heads and the long crankshaft.

An LQ4 from 01-07 Classic body style or LQ9 from 02-07 Classic Body style will swap right in.

As mentioned, the LQ4 will need the spacer removed and to use the old fly wheel from your 4.8L.

 

This thread is full of good factual information