So how will a iron 5.7 with the truck heads, patriot 226, ls1 intake, mac mids, e-fans, and a good tune perform? Might do a little porting on the intakes on the heads. Say 350 to the rears with a a4?

 

That sounds like an easy goal to reach, really. Head work is what will be able to make some good power. But why the LS1 intake instead of LS6?

 

Can't afford the ls6 right now I will have one on there a little later down the road.

 

Let me know if you decide to get one. My buddy had one for sale a week ago. The map sensor piece on the back is broken, just like 95% of them, but that just means you get him to drop the price $20. LOL!

 

I wish I could afford one right now but I still have to buy a stall, fuel pump, have the exhaust ran, etc.

 

Going to be doing the same build here from a 5.3l to a 5.7l
want to make an engine boost bullet-proof.
Are stock 5.7l pistons worth a damm for boost up say 12 psi max??

 

The LS1 Intake flows worse than the stock truck one, go LS6 or LS2

 

Is this something to worry about as far as balance goes??

5.3L Cranks
The 5.3L engines all came with automatic transmissions, so they all had the 12552216 casting with the narrow flange. This is the same casting that was used in both the 5.7L and the 6.0L, but it's balanced specifically for this application, so it has its own unique GM part number. We don't know what the bobweights are, but our sample piston weighed 406 grams.

5.7L Cranks
The 5.7L had the same stroke as the 5.3L, but the cars always with came the narrow flange, so it had the same 12552216 casting that was used for the 5.3L and 6.0L. The 5.7L cranks weighed about a pound less than the others because they had a 24.5 mm hole drilled right through the center of the second, third, fourth and fifth journals. We're pretty sure that the balance was unique to this application, because the pistons weighed 434 grams which is more than the 5.3L and less than the 6.0L.

Taken from this article.
http://www.automotiverebuilder.com/ar/eb040538.htm

 

i did the 5.3 to 5.7 last year with a tr224 cam and a 3800 stall. it ran 8.40s with stock manifolds, stock intake and stock 241 heads. the rods and pistons were stock 5.7. never had a cooling issue either

 

Of course you're gonna get them balanced at a machine shop, so don't worry about it.
And stock LS1 pistons suck. Go forged. New forged pistons are only about $550. Why go cheap on such an expensive project?