is the 5.7 any lighter than the 5.3? I'm not sure what the 5.3's block is made out of

 

5.7L is an aluminum. 5.3L is an iron. The 5.7 weighs about 60-70lbs less.

Here is a picture of one in a truck guys (with an LS6 intake manifold)

 

the concensus seems to be a 5.7 will be faster than a 6.0 just droping both in but i have to say my 6.0 runs prety strong. seems to me the 6.0 heads are better and the extra .3L can't hurt. 6.0's are damn cheap to find too.

 

anybody with a 5.7 swap tell what there gettin gas mileage wise?

 

Yep, the 5.7 being aluminum and 5.3 being iron will be a huge difference in weight. It is also as much difference in cost, too. There are waaay more 4.8/5.3 blocks and motors for much less money. There is also the benefit of strength with the iron vs the sleeved aluminum blocks. All in all, we'll see what the end result is. If it is financially feasible to go the 5.3 bore out route, it will add another option for LS1 conversions and hop ups. I will post the end result, hopefully in the next month or so.

 

hey scream... you gonna put a z28 decal on it now?.... heheh

 

How do the gas mileage on both compare with say minor mods(custom tuning, full exhaust, intake, pullies)? Comparing the 5.7l and the 6.0l.

 

ktmrider....you bored a 5.3 block .118 over ...sir I to you for having ***** that big !!!, you also said that the current wall thckness was .250 and min. is .150...does that mean the 5.3 block will go .168 over on a bore for a total of 3.948 bore size ????

That 3.948 bore with the stock 3.622 stroke will get you 360cid (that's 4cid less than a 6.0 guys)...add a 4" stroker crank and you have a 400cid motor...out of a stock 5.3 block !!!!....holy shiznit, if that's true somebody try this !!!!

so...what kind of overbore will the 6.0 take ???

 

I'm probably going to start building a N/A beast this summer. Boring out a 5.3L block and all forged internals, sweet cam, tuning, heads, headers, etc....

 

Ummm....NO!

Maybe a Z-78? LOL