i have been readin the bloggs about the 4.8 and the 5.3l engine bein the same just a different stroke .... so what do i need to do to change the 4.8l to a 5.3L

 

I believe all you would need, would be the crank and rods.

You could re-use the 4.8's flat top pistons and get a bit more compresion out of your 5.3.

 

so do i need to do any machine work or boaring of any type

 

To do it right you'd need new main and rod bearings and new rings, then have the block honed. Since you have to disassemble the block to have the machinework done, you'd also need new head bolts and a full set of gaskets. Bore is the same. Probably not worth the money to convert one to another. You should be able to pick up a good running 5.3 long block for less than you'd spend to convert the 4.8 to a 5.3.

 

Or just bypass it all and make your 4.8 a 5.7L.

 

+1 thats what I'm working on. It's gonna be sweet.

 

i think the 5.7 from a 4.8/5.3 would be bad ***!