I have an ls1 with 68k miles on it that came out of a crashed C5 (the engine ran but is in unknown condition, however the car seemed taken care of). I've stripped it all down and sent the heads to AI. I planned to leave the short block as is (no new parts or machining). I bought a couple books but they all focus on a ground up rebuild none address a rebuild with a used block. So what should I do and what shouldn't I do to prep the short block for reassembly.

I got concerned when I read that prelubing a reassembled engine that wasn't tanked could loosen **** in the galleys and destroy an engine. Which made me think I should remove all the plugs and do some cleaning. But If I'm not breaking down the short block and tanking it, I'm not sure how effective I could clean it and might even make things worse? I would like to flush coolant and oil galleys if possible and get everything clean without pulling piston caps etc. I've already cleaned the deck surface.

 

If it was in good running condition, then I'd leave it alone. Inspect everything and do compression test (you should have done it before removing the heads). Once you take it apart, it opens a big can of worms. It will need to be hot-tanked, then you may as well hone the cylinders for next size ring set, new cam and main bearings, plugs, gaskets, barbell, oil pump, etc... On and on it will go, so just put it together and run it when your heads come back.

 

FYI...I'm doing a cam swap, so while there I will be changing out timing chain and front/rear seal. I'll have the pan off and can do some inspecting.

I totally understand the can of worms on disassembly. But to clarify should I not replace the block plugs (or just barbell?)? And should I not prelube once fully assembled? I've got a new Melling pump going on also, If I don't prelube should I pack or prime somehow?

 

If it's not leaking or broken, then leave it alone. You can prelube after it's all back together.