I will take some pics of the piston-rod assemblies tomorrow.

I agree with Mike, looks like heat checking to me, a good std std GM fordged crank may be in order, and Randy we knew u pulled the bolt first.

just fyi,gm bought the gen 5&6 cranks from scat.

couple of things...need to have a machine shop ck the crank for size/round and the rods as well, I have run into scat and other cranks that say factory balanced be totally crap and have a tuff time getting them to balance at all, can't imagine what they would be like run as is...backfiring had nothing to do with the bearing/vibration..good luck Rob

So a Kellog stamped crank is from Scat ?

when you see that shade of gray,,they're all from china.
scat cranks are usually alright,a touch on the high side but have been way better than eagle.

Yes, Im aware of that, but it didnt answer my question

[ATTACH=CONFIG]527218[/ATTACH][ATTACH=CONFIG]527215[/ATTACH]

[QUOTE=Randy Nielsen;4160844 The crank was replaced & short block built 5 yrs ago then stored until last yr then everything disassembled cleaned up & reassembled, dyno'd now this.[/QUOTE]

I must have missed this.from the markings on the bearings,this crank/bearing clearance is a miss.
do you remember measuring this crank and adjusting bearing clearance.

yeah,I don't know that,,maybe RMbuilder can answer that