I am semi restoring a 1984 SWB c10 that I want to install a carbureted LM7 in. This will be a get it up and going type build while I sloooowly build a turbo motor on the side. What kind of shape are yawl finding these motors in say from 100000 to 150000 miles on them. Will they take a freshening up such a ball hone to the cylinders, re-ring, new bearing and gaskets or are they pretty much machine shop bound at that point. I'm finding some engines but they're in that mileage range or no miles listed. thanks for the help.

 

I've heard lots of times people not even touching the internals below 150k....

It's been said many times that these motors are good for 300k miles, so it's not quite like the usual SBC's needing rebuilt at 80k.

 

condition varies depending on what type of use the miles were made up of , stop and go taxi with 150k will show more wear than highway commuter with 150k.

theres junyard dog builds in conversions section where they boost 250,000 mile unopened engines into single digit et's

My current ls engine stable includes a 239,000 mile bolt on m6 z28 that has never had a valve cover off it ( ran 11.9 stock internals for previous owner), a 173,000 mile bolt on stalled auto that is also unopened , ran 12.1 for me 2 weeks ago on its first track trip , my 2500 hd that I use to tow everything around has 180,000 miles and I dont think the spark plugs have ever even been changed- they havent since I bought it with 120k , theres some ls engined work trucks/vans all over craigs list with 300,000+ and still going

I had similar experiences with series 2 3800's supercharged engines (also crossbolted mains) , owned many with over 200k ,sprayed one of them pretty hard too lol.

save the machine work for your "build" thrash the cheap junkyard hi miler your looking to buy and I bet it holds up surprisingly well

 

My LM7 had 140k on it when I got it, I have put 5k on it and the last 1k has been on 8lbs of boost with a Magnacharger... These motors are tough.

 

Thanks guys that helps a bunch as I'm new to the ls motors. I'm selling my big block that was going into the truck in favor of a high revving ls small block. Looks like I can start paying more attention to these higher mileage engines.

 

Mine has 101k and still rides like new, although I still wish I had lower miles lol.