Every dyno Ive seen is 25-35hp. Stock LS truck intakes are terrible for power.

Buying used 243 heads is 400-500, plus gaskets, plus bolts, plus lots of work involved.

Either way, I think the head swap will give you a nice gain!

 

The stock truck intake is almost as good as the stock LS6 intake and better than the LS2 and LS1 intake.

If you don't already have the heads why not take the money and have your stock heads ported? That would likely gain more than a stock set of LS6 heads.

 

Yall fail at reading... He already has the heads

 

the 862 are poo. why are you gonna mention a 1000 intake when ALL he wants to spend 500 on a complete upgrade.

mill your heads, grab a set of head gaskets, ARP head bolts, an upgrade intakes if thats what you want.

my L92 has a stock truck intake an it spanked a 2010 Camaro SS tonite from a 25 punch and a 55 punch.

 

the 862 are poo. why are you gonna mention a 1000 intake when ALL he wants to spend 500 on a complete upgrade.

mill your heads, grab a set of head gaskets, ARP head bolts, an upgrade intakes if thats what you want.

my L92 has a stock truck intake an it spanked a 2010 Camaro SS tonite from a 25 punch and a 55 punch.

 

Mine are 243's UNTOUCHED ports but milled .035
Did good on the 5.3 and on the LQ4 now,but they will be ported sometime soon when I get time to rip them off.

 

Weatley do you think the heads milled will net him his .3 like he asking for? youve tuned a ton of different combos i wonder what works best for the DD side/roll racer. his truck is a beast for a small cam/tight stall/3:42s! which traction id pull him but if i spin hes already gone an my big ole truck cant catch him before 100

 

3 tenths is asking alot just with a head swap.. its gonna take more than just slight flow numbers to make a difference, its gonna take the rest of supporting mods to get there..but dont get me wrong its possible since youre upping the compression, how much you'll gain will only be defined once you go to the track on simular days. your heads probably wont work to its fullest potiental cause of the cam, the intake, the gears and so forth

 

It can happen but I would not expect quite that much.
I would have them milled to bring the compression up some.

 

There ya go,it's all in the combo!!