im planning on removing my stock 4.8 aluminum heads
i need info on opinions on should i rework my stock heads or buy 6.0 5.7 or 5.3 heads and what combo should i use i dont want n.o.s. or forced induction so all opinions will be greatly apprecatied...

 

6.0 have the best flow #'s, from what I have been told.

 

actually the 4.8/5.3 heads are the same and are a very good head. all the other heads have bigger cc chambers and would drop your compression.61cc 4.8/5.3 64cc 5.7ls-6 67cc 5.7ls1 71cc6.0. go w/ 4.8/5.3 heads have them cnc'ed. you can't go any bigger than 2.00" intake w/the 4.8/5.3L bore. have the chambers reduced to around 58cc to bring you up to around 10:1 compression. then add a cam that will take advantage of the increased flow but be careful of your .050" duration #'s too big and you'll kill any of the low end the 4.8 has.

 

I know that with 5.3 heads if you get them reworked you can get up to 12:1 compression I believe, and will work with 93 octane. Not completely positive but pretty sure.

 

The thing to do is put the 4.8/5.3 heads, with some port work, on a 5.7 for the bump in compression. That tells me that the 4.8/5.3 heads are good flowing heads. Have the heads worked over by some one that knows what they are doing.

 

Flem has some excellent advice on this. Bumping up the compression is a good idea for a n/a motor.They make 2 6.0 motors. The only difference is the compression. One makes 9.5:1 and the other makes 10.5:1 and claims 340 HP.

 

4.8/5.3/5.7 heads are the same. The diff is the combustion chamber between the 4.8/5.3 and 5.7 (LS1 heads)

LS6 and 6.0 heads are the same also with the difference being the chamber also (same "D" port exhaust).

 

minor difference...but it's 9.4:1 NOT 9.5:1 and 10.5:1 for the LQ4 and LQ9 6.0 liters...I have been told the difference is in the head gasket...and I have a hard time believeing that 45 HP is gained by a head gasket change.....I am assuming there is a cam change as well ??

 

Yelo - Same head gasket in the different 6 Liters. Same cam in the LQ4 and LQ9. The LQ4 has cast dished pistons for 9.4:1! and the LQ9 has hypereutectic flat top pistons for 10:1 compression. The 45 HP rating is due to the increased compression and better tuning.

 

thanks for the correction and the info.....I thought the head gasket thing sounded a little fishy