I’m looking at an 86’ LB PU and am just searching for info on the 6.2’s
durability. From what I’ve been told the 6.2 is long lasting, but to me
that means head work at 350 and don’t worry to much about the lower
until you get to 500. From what I’m reading here these aren’t getting
that – well they’re not much over twenty years old from new now, so
maybe it’s a check back in fifteen years kind of deal.

I’m reading that the harmonic balancer causes many failures – Why? I’m
a little unclear on this. Are the lower ends weak? Is it not a solid
pulley? Maybe I don’t know what’s being talked about? Isn’t the
balancer just a big crankshaft pulley?

Is there a year or series to look for or be wary of?

No it's not solid, got a big block of rubber in center to dampen crank pulsations and piston hammering on the crank. As they age the rubber gets cracked, some conventions of thought are once rubber is gone or damaged harmonics taken up by the rubber transmit thru the crank causing it to break.


Cost of damper new isn't that much pretty cheap insurance over broken crank and work to replace it; Some say replace at 100K, I think you are probably okay with in depth visual inspection at every oil change, look for swelling or cracked rubber, if you see that plan on getting a new one ASAP. I would not install a junkyard one myself.

Thanks – the lights just came on. I see it now. So is this the way all
harmonic balancers are? If so, why is this more of a problem – or is it
– on this motor?

The one thing with a diesel engine is there is a crap load more internal pressures and vibration than your tipical gasser. This would be a problem with a gasser but it would probobly take loger to do the same damage. It would be the same deal with a hoped-up gasser with 14-16:1 compresion since diesel engines run 17-22:1 compresion.

Gm lowered the nickel content of their blocks because it was only sapposed to make 135 hp. The '82 and 599 block plus the newer AM general blocks have the best block strength/highest nickle content.