8.1l 120k Replace Top End Only?

[TravisAZ]

This is a cross post from the HD section

 

Hey guys - Im trying to run down a mysterious coolant leak in my 8.1. We wont get into the details of that, but lets assume blown head gasket or cracked head or something that requires me to get that deep into the engine.

 

If I am going that far I figure I should go with either the dart heads + cam or the raylar head/cam combo.

 

Ive always heard it isn't a good idea to do the top end of a motor with this many miles on it (120k, and ive owned for 10k of that). Of course a head/cam swap is a weekend job that I am confident I can handle, but a motor swap would probably at least quadruple the cost, and frankly I would probably be better off just replacing the head gaskets and trading up into a different vehicle. Its in a 2001 yuk xl 2500.

 

I tow around 8k lbs and prob another 1k in the yukon, and I haven't been blown away by the towing performance of this particual rig yet. It does ok, but I wouldn't mind adding another 100hp to the equation which I think should be possible through a head/cam/tune - just worried that the bottom end won't handle it.

 

What tests would you do on the bottom end to feel confident strapping some new heads/cam on the top, and what results would you be looking for? Compression, leakdown, ...???

[jmilana]

My guy says he's done several and they become oil burners after doing just the top end. I have the same problem