4.8/5.3 differences and interchangability

[GeoffP]

Can anyone tell me the internal differences between a 4.8 and a 5.3? I have a chance to buy a long block 4.8 from my work with a bad cam for $285 (core). I'm curious if the internals from a 5.3 will work in the block or how hard it would be to upgrade the block to a larger CI. Worth the expense to buy this and put it up for later or no?

Thanks!!

[cantvalve16]

I got my info from LS1tech.com. If you look on the block, you will see a casting that says 4.8/5.3. Those engines use the same block. The bore is even the same between the two. The size differnce is in the crank and the rods. Swapping a 4.8 crank and rods for a 5.3 crank and rods will get you a 5.3.

However, the block can be bored a little and you can use a 5.7 LS1 crank and rods to get you 5.7 displacement.

I am impressed at how versitile and stout these engines are. Continually amazed.

[GeoffP]

So how good's the cylinder thickness if you punch it out to accomodate an LS1 piston?