07NBSChevy

iTrader: (1)

Hey guys, doing a cam swap (BTR Truck Stage 2) on my 2007.5 NNBS Silverado with a Gen 4 LMG 5.3 with 108k miles. When removing the old cam I noticed the bearings had a little more wear than I would like, I can feel slight grooves in them, so I am going to replace them with some Durabond coated ones. I notice they sell the CHP-23T and CHP-25T. I was told the 25T is for 2007.5 and newer gen 4 4.8/5.3/6.0 truck motors and the 23T is for the LS2/3/7 car motors, is this correct and I should get the wider 25T ones?

Another question, am I able to change the cam bearings without removing the crank, rods and pistons?

If not, I was planning on using the Clevite H-Series Coated bearings. For the Rods I was going with CB-663HN, which is their narrowed version, I guess for less drag from what I was told. For the Mains is their MS-2199HK. Both would be in standard sizes. Would I need to do anything else other than check clearances for using the H-Series coated bearings or should I stick with their P-Series bearings. I also was told their H-Series has a chamfered edge or something like that. I am using the stock crank and rods. It is a iron block as well if that matters. Estimated crank HP when done, 420.

Thanks in advance guys!

07NBSChevy

iTrader: (1)

Let me start with this. I have had 2 LS techs tell me these cam bearings are good to use. They have these odd, what appears to be, machine marks on them. The marks are on every bearing in the same location and all bearings pretty much look identical. The cam has no wear on it but i am just worried about using these if they are worn bad. I will upload some pics and you guys let me know.

07NBSChevy

iTrader: (1)

Well believe it or not, the bearings are supposed to have those marking in them. Had a GM Engine tech look at it and he said they did that on the Gen 4 LMG 5.3's for oiling. He did some measurements and they are well within spec and look to be in great shape.