Shit you don't ask for much do you
400k on a Cruiser is just run in. Bodies don't rust like pootrols.
Look for a 24V if you can. The 12v have issues with big end bearings failing with higher ks. Not a big job to replace though if needed. Might get a better deal on a 12v due to that though. If the oil pressure guage flucuates or doesn't move off lowest mark when idling, it is normally a sign they need doing.
You will definately want a turbo as well GM. Anything to help you move faster ........

Watch out for front drive flanges wear and they can loose drive if bad enough, geing permanant 4wd.
There are kits available to make them 4wd/2wd selectable. It's not just a matter of fitting free wheeling hubs.
Ice box in the centre consle is very handy for cooling beverages.
Have a good look around where the steering box mounts to the chassis. The welds crack and the chassis needs welding and strengthening. Problem more prevalant on trucks with big wheels.
Triple diff locks are very handy if you can find 1 with them. Very sort after so prices are much higher though.
They can blow smoke when cold. Typical Cruiser type thing. When warm they seem to be OK.
Look out for any fuel leaks from the injector pump. We seem to have done a few over the last few months. Not just top gasket either. Need full strip and o/haul.
P/s pumps can leak, but easy job to rekit.
We have trucks that come into work that have done over 500ks and still going strong.
Bookmarks