This is from enginetechs catalog part lookup on their website

 

Called the machine shop....after dealing with the ***** on the phone he finally went and got the build sheet. They are the Durabonds CH-23. Horrible customer service. Never using them again.....

 

The 23s should be for gen 3 blocks... The 25s are for the gen 4

 

So they do need to be changed? He claimed the thickness wont matter.

 

As many issues as the gen iv engines have with cam bearings i want the proper bearing in there

 

Gen3 cam bearings are way smaller than Gen4's. Impossible to install them in the wrong block. I installed the narrow Durabonds in my LS2 a couple thousand miles ago and it's doing fine.

If it will make you sleep better at night, throw some wider bearings in there. The machine shop did nothing wrong, imo.

 

Not saying the bearings are wrong and wont work, or anybody did anything wrong... i personally would just prefer the wider bearings the gen iv blocks call for with all the issues they have with cam bearingsto begin with!!

 

After thinking about it, I think the only reason wider cam bearings were used was because of the big *** groove cut in VVT camshafts.

 

Oh you mean the oil robbing groove that all the vvt and afm cams have, could very well be the reason they went to the wider bearings but iirc the cam journajs in the gen iii blocks are narrower too, could be wrong been a while since i pulled a gen 3 down at this point and when i built my 6.0 in the 99 i wasnt into taking pics of everythingthe way i am now....