eb02z06

iTrader: (18)

My question about the 5.3L block is did they ever come in aluminum and can they bored out to 3.905? Does anyone have a part # for the block? Is it even worth it-I can't seem to find a good used 5.7l block-I just want to build a good forged bottom end for FI. Also does the stock 5.7 crank and rods interchange without any issues? Thanks!

kossuth

iTrader: (12)

I've heard they can be taken over to 3.905 but that's it. It gets kinda shacky after that. Check with the guys over on truckperformance.net they will have a better idea. Crank will bolt right in no problems.

8a8mfh

iTrader: (3)

Don't limit yourself to a 5.3 block. The 4.8 blocks are the same. If you look at one you will see, behind the flexplate, it will have 4.8/5.3 cast into it.
There are a few aluminum 5.3 blocks out there accoring to this site.

eb02z06

iTrader: (18)

But can the aluminum blocks be bored out to a 3.905-are they same as the 5.7 but with just thicker sleeves?

8a8mfh

iTrader: (3)

I doubt it.....why not just get an aluminum 5.7 block (LS1,LS6)and not worry about the overbore?

Steve - Race Eng

iTrader: (1)

The 5.3 liter block has thicker cast in sleeves to reduce the bore size. It is identical to the LS6 block otherwise. You can indeed bore and hone it to get a 5.7. You will have to compare costs to see whether it might be less expensive to just buy a 5.7 liter block in the first place.

Steve