I have a ls 4.8 block and i dont know what i should heads i should uase the 317 or 862

 

Care to give more than just that?

What cam?
What intake?
What fuel?
Staying NA or going turbo/supercharger?


There are better heads than those when just comparing stock heads. 243/799 heads are better than 706/862's.

 

generally speaking the 317 is going to lower compression so much on a 4.8 that I wouldn't run them despite their large jump in flow over the 862.

 

If you want to run 20+psi on pump gas go with 317s.

 

317 heads on a 4.8 might as well put a magic stick in there too

All jokes aside...

Personally I would a PRC 5.3 2.5 and mill them .030 then toss a 212/218 600/600 112 in there and let it ride.

If boosting... PRC LS6 2.5 at 64cc and use the same cam as above on a 114 LSA.