Other than weight difference, are the aluminum stock LQ4 heads worth a 200.00 (used) cost upgrade?

 

IMO ditch the 317s get a set of 243s they flow about the same as the 317s but teh 243s will bump up your CR. also aluminum is better than iron due to is ability to Disperse heat better

 

Correct. Iron is a good 100lbs heavier and will get hotter than aluminum. Also If you have an iron headed Lq4 (99-02 IIRC?) you will need a crank adapter to fit on a 4L60 if you are planning on using one.

 

not necessarily get hotter but hold heat in-which is what you don't want. Aluminum heads will dissapate heat much faster and as a result may allow better timing, all things other being the same?

 

Thanks all. And I've learned the hard way about the 4L60 already and it's now up for sale. Scored a 4L80E with a fresh rebuild from a '99 C3500 that was bolted to a 454 for 300.00.

 

You're backwards

4L80E's used the adapter, 60's didnt. He'd have to change cranks to run a new style 4L60E. The LSx 4L60E's used a special converter with a longer snout to make up the difference. 80's used a conventional converter and required the adapter to make up the difference

 

Circle-D or Yank could make a custom torque converter if the need be...

but anyway, back to the heads, here's the scoop:

As Bill said, if you can keep your combustion chamber cooler, you'll have less chance of detonation and be able to run more timing=more power...not to mention the weight difference