Changing a 5.3 to a 5.7 Q's
 

Didn't see this catagory to show a 5.3, but it's basically the same.

I traded a Vortec 350 for a 2003 truck 5.3 motor and since the kid lied that it was a running motor, It's gonna need a rebuild. Haven't gone through the lower end yet, so it's assumed that the stock bottom end will be used also.

The casting #'s and info says that the block can be bored out to 4" for a inexpensive LS6 build.

SO, does anyone know which pistons to use?
Do they HAVE TO be same year? (camaro or corvette) or can I use earlier model std size pistons from pretty much any chevy 350 motor?

I'm going back with the rest of the 'stock' engine parts as in heads, pan front cover... Well, the cam might be swapped for something more 'energetic'

Thanks E

Re: Changing a 5.3 to a 5.7 Q's
 

OH, Sorry. I forgot.. I'd need the crank to right?
Or would I be able to make a big bore 5.3?

E

Re: Changing a 5.3 to a 5.7 Q's
 

The crank and rods between the 5.3 and 5.7 are the same so no you won't need a crank. You will need to have it balanced though. The Pistons I'm not sure.on but its better safe than sorry.

Re: Changing a 5.3 to a 5.7 Q's
 

4" bore from a 5.3 block? :no: You're probably confused. The LS1 and LS6 are 5.7 liter engines, but they do NOT use the same 4" bore of the older 5.7 liter 350" SBCs. Other than lifters and bore spacing, they share nothing in common.

You can safely go to the LS1/LS6 bore of 3.898", or to 3.905".

Re: Changing a 5.3 to a 5.7 Q's
 

NOPE, not cornfused.. That's what 2 different books state. OH, and it's the 4.8 and 5.3 that use the same blocks. (hence the same stampings on the block front and rear)
BUT, they DO say that my particular block can be bored out to make a 5.7.

And, are the LS based 5.7's actually a 346ci instead of a 350ci?

I just want to know what pistons that I'd have to use to make a 5.7 LS engine from my 5.3..?

Thanks E

Re: Changing a 5.3 to a 5.7 Q's
 

Yes, you ARE confused. They CAN be bored out to make a 5.7L: a 346ci 5.7L with a 3.898" bore! You need to do a little more research on the Gen III engines.

DO NOT BORE THE 5.3L BLOCK OUT TO 4.0"!!!!

Again, you need 3.898" stock LS1 pistons, or 3.905" pistons which have multiple aftermarket choices available.