kmspruill242

Might have a chance to pick up some heads from a shop. They had two blocks on the shop floor. One was a 5.3L and the other was a 6.0L both had heads with 243 stamped on them. What are the differences and which would be better if at all? I may not have a choice on which, if any, set I get but any info would be cool just in case. Thanks guys...

k5383

iTrader: (10)

From what I know, the 5.3 heads yield a higher compression ratio over the 6.0 heads.

nightmare23

iTrader: (5)

actually i think both are a 64cc unless ur talking about the 317 which are 72cc

hlaalu

iTrader: (3)

but if they are both 243 heads, they should be the same heads?

rtr2001ss

iTrader: (2)

Actually from the OP's post it looks as though the 2 motors in question are a LS4 and a LS2.

Far as I know the 243's from both "Should" be the same, as well as the LS6's.

nightmare23

iTrader: (5)

yes sir .. tru ls6 heads have the sodium filled valves the ls2 dont ...

LS1 BU

iTrader: (13)

They are the same. solid valves. Also 799 heads come on newer 5.3 motors. They are the same as the 243 also. I run the 799's on current motor.

kmspruill242

That's what I thought. I knew the LS6 heads had the lighter valves but I'm not worried about that. I read the 5.3L heads might yeild a higher compression, but that seems to be a toss up. I'm still going to get basically the same gains with them being 243 heads correct? As in it's worth it for me to get them and replace my 241 heads...

Thanks

kmspruill242

Also would it be worth it for me to grab the intake? I've only got an LS1 intake to bolt back up. This Im just throwing out there, I have done zero research on 5.3L intakes.

rtr2001ss

iTrader: (2)

5.3L intake won't fit in your car. Stick with the LS1 or upgrade to LS6.

kmspruill242

Got it. Thanks bud.

Ws6kid.

What heads should i run if im planing on getting a super charger?

Wannabe ls1

youll want the lower compression ratio heads if your gonna use boost

02*C5

iTrader: (1)

Go with the 317's they have a bigger chamber and you will be able to add boost with little worry.

Ws6kid.

Thanks. do 317 make good numbers compared to the 241 heads?
would they make a nice combo with a nice boost friendly cam?

SOMbitch

iTrader: (8)

317's are 243 ports with a bigger chamber to lower compression.... They are found on 6.0 truck motors.

EDIT: They work very well with F/I because you can run more boost before you have predetonation issues...

02*C5

iTrader: (1)

Like the post above they 317's are 243's with larger chambers. They can handle more boost with out predetonation and a lot of the guys who run ZO6 heads (243s) and are wanting boost on their F bodies or Corvettes go to the 317 as a budget head for boost. 317s have all the qualities the 243 has, but can handle boost because of their 72CC chambers. All I would do to those heads would be CNC, post & Polish if your are going for boost. No need to mill the deck what so ever. If you get a wild hair do .005 off the deck and that's it no more.

By the way 241 heads do not flow...at all...what so ever...they are not good heads...did i say that already.

Oh and before I forget the 317s have smaller valves so you can't just automatically replace the valves with bigger valves you will have issues. Its should go with out being said but had to mention it.
good luck.