Like the title says, is it possible? I was looking for forged pistons and it seems like all the big names, Diamond, Lunati, JE, etc. only make them for the LS1 5.7. I believe the 5.3 is a 3.84" bore and the 5.7 is a 3.903" bore. The stroke for both engines are the same.

 

You'll only find the 5.7 pistons on the store shelves, but they can make any size you want when you order.

But yes, the 5.3 has enough meat to handle a bore out to 5.7 specs (3.905 for off the shelf pistons). I think the user RECKLESS had a 5.3 block punched out to 5.7 for a power adder.

 

It may be possible but who will do it? I have been all over trying to get it done and nobody will touch it. Any ideas on who will? Im in FL.

 

Would it not be cheaper just to scoop up a Std bore LS1 or 6.0 motor? Than to machine a block down like that.

Won't it need new sleeves and stuff too?

 

I don't think the 5.3's need sleeves, arn't they steel blocks?

 

Oh, well a .060" overbore is feasible I'd think. For somereason I was thinking on going to a full 4" bore on a 5.3 yeah see what sleep deprivation (sp?) does to you.

 

The 5.3L block doesn't need sleeves to be taken out to 5.7L. Reckless did this a while back and evidently that is the farthest you want to go on the bore but, it is possible. Not sure on the 4.8L block if it's possible, for some reason I seem to remember something about different cylinder liners being used that won't go that far??

 

4.8 / 5.3 block is the same part number. I think block is stamped for both.

 

So to use standard 5.7 pistons you must bore .060 over?

 

Tex - That makes sense.

Benpimpin1 - No, more like ~.120 over.