Worst years for Castech heads?

[Jester1023]

Another Castech head question!I’m on the hunt for A NBS Z71 I’m looking at years 03-06 I prefer the higher gears in the 03/04’s as I want to run 33’s and almost all the ones after 04 I see have 3:42 gears though I’ve read the 05/06’s are the best of the NBS lot!

my question is with the Castech heads is it a roll of the dice or are certain years more prone to having the 706 faulty Castech’s over other years?

Thanks

 

[Mudsport96]

I think its pretty much pre 03 heads but dont quote me

 

[mattbta]

Doesn't seem to matter as there have been reports of 862's cracking. My 2004 706 castech cracked and a refurb castech cracked.

 

[TJ Baker]

My 05 LM7 has cracked Castech(s).

 

[Jester1023]

Gotcha so it’s pretty much a roll of the dice I’m approaching 200k on my Yukon with no issues I do have 862’s.

thanks for the replies

 

[tRidiot]

My '04 706s cracked at 275k. They were leaking some before that, but I just kept it filled up. Then I swapped out a thermostat and next thing I know, *BANG* - blown head gasket per repair shop.

Currently looking for a decent LQ9 motor to swap in and get away from Castech for good.