I know this has been asked time and time again but I can’t find the answers I’m looking for. I know the 6.0’s in 99-00 had a little longer crankshaft, but is this the same for 4.8/5.3’s that are 99-00 or are all these cranks the same size?

 

If you are referring to length at the tail end, Only some of the 4.8L cranks had the longer rear snout on the crank. I believe they were paired with a manual trans in the truck applications for 99-00.

If the 05 engine and trans combo was originally from a van it should already have the spacer and flat flywheel on the crank. If it was originally in the truck and he swapped in a 4L80E anything is possible.