I'm picking up a 6.0l friday and maybe some ls6 heads saturday and was wondering what compression would i have with those heads?? I would like to have around 11:1..thanks

 

Is it an lq4 or lq9? LQ9's have flattop pistons and 10:1 compression with the stock heads. Not sure how much compression you'd gain exactly by going from a 72 cc head to a 64 cc head but you'd probably be close to the 11:1 you're looking for. An lq4 has like 9.6:1 or something like that so you'd be a little further away.

 

not sure yet?? I believe its the lq4 but i will know friday!! Can i use the lq9 pistons if its an lq4??

 

Yes, you can.

 

I believe with an LQ4 + ls6heads will get you from 9:6 to 10:1, and I believe if you milled the LS6 heads .030, then you'll have 11:1 on the LQ4. let someone else chime in to correct me if needed.

 

those heads on a LQ4 would be around 10.4.....if a LQ9 then youll be around 11.1

 

thanks guys.its an lq4 with cast iron heads..yuk!!but i pick up a set of ls6 heads tomorrow and buying flat tops.What do u think cast iron 6.0 heads are worth??And how much horse do u think stock rods are good for??
And Quick that motor sounds sick!!!and not in a bad way!!lol sounds like my old race car!!

 

Cast iron heads are worth more as scrap then you'll get out of selling them. I've got a set sitting in my shed that nobody wanted. They really don't perform that bad though. I did some research on them when i had them on my turbo 6.0 and found that they are the same casting as the 317's but made of iron. So the only real benefit is weight savings and you can push compression a little higher with aluminum.

As for the rods, i've seen people pushing 500+ HP on them. But for the relatively cheap cost of some eagle h-beams i'd go ahead and replace them for piece of mind if your going to have it torn apart anyway.

If the engine had iron heads then the crank is longer, made to be used with a 4l80e. If your not using a 4l80e or th400 then you will have to replace the crank with either an aftermarket one or a 2001+ model crank.

 

your crank will probably give you issues in the Ironhead motor, it sticks out roughtlly 7/16s". dpending on trans you plan on running your might have issues

iron heads worthing nothing, unless looking for someone that had an issue with a previous head
rods should be fine if anything the bolts should be replaced


thanks for the compliment on my old setup