i keep hearing about a bad batch of heads called castechs? What year engines were they on so i can avoid getting an engine of that year..?

 

706 casting 99 up gen 3 heads. Not all of the 706 heads were castech though. If you do a search someone posted about what the casting mark looks like and where it is to id a castech vs non. Hope this helps

 

99-up, all the way to 2006? man, that sucks because was looking at engines on e-bay because there are non around here, so i would be taking a big chance not being able to look at the heads, crap!

 

The 5.4 in my Suburban has a LS1 gun drilled crank, over 10k miles so far and no problems or vibration.

 

All you need to do is ask them to look at the 3 digits cast on the outside. 706 and 862 are the ones that would apply to 4.8/5.3L some of the later engines got a 799 casting which is identical to the 243 heads.

 

I said prudent, not that it wouldn’t work. Anytime rotating assembly components are swapped from one engine to another, balance should be checked. Just because in one case it worked out doesn’t mean I would go around recommending it. However in the case with the gun drilled vs solid cranks the metal being removed from the centerline, it doesn't have as great of an effect as it would if the metal was removed from one of the rod throws or counter-weights.

 

Well Said!!!

 

My comment was not argumentative, simply stating that for a mild engine in a daily driver the crank difference is not a big deal.

 

I understand, but so many people do misunderstand others statements and would turn it into something it’s not meant to be and we all know how assumptions go. I read it on such and such and next thing you know it’s the gospel.

 

As mentioned "in general" it is a good idea to have it checked for balance for your application. It may work just fine, but the weight of say a 5.3 piston and rod is different from say that of a 6.0L.

No harm no foul