4.8 vs. 5.3, same truck and gearing...?

[RedHeartbeat]

You are so misinformed.

[TXSZ66AVLANCHE]

I went from a 4.8 to a 5.7 and my mpg (under normal driving) actually improved. Stock 4l60E with 127k has held up just fine, so far I've had the combo for 10k miles and beat on it daily.

[bstill]

so ive been doing some more reading on this swap and its getting more complicated, not only did the early 6.0's have a longer crank, but so did the 4.8 and 5.3 also! My truck is a 1999 so the 4.8 in it is going to have the long crank, meaning the flexplate in it wont work with the 6.0...

The 6.0 had the longer crankshaft in 99 and 00 so that it would fit on the shorter snout of the 80e converter. In 01 they did away with that crankshaft and just used a spacer to make up that difference.

The 5.3 and 6.0 crankshafts have the same dimensions, so it makes sense that they did away with it in 01 and used the spacer.

[mopower440]

I also see that they did away with the EGR in later year engines, if i get an engine without the EGR, what do i do about my truck and PCM that is used to having one (truck is a 1999)?

[blacstar]

I also see that they did away with the EGR in later year engines, if i get an engine without the EGR, what do i do about my truck and PCM that is used to having one (truck is a 1999)?

a tune will fix that!