Hey guys Im going to look at a 5.3 I found on craigslist either tonight or tomorrow. Problem is I dont know how to identify that its a 5.3 and not a 4.8. What do I need to look for?

 

https://www.performancetrucks.net/fo...hlight=pistons

To add. IIRC 4.8 should have flat top pistons and 5.3 has dished. 4.8 has higher compression because of this.

 

Thanks but I could use some more info on the "inscription on the bottom right hand side of the block" Is this going to flat out say 5.3? I cant check the bore or stroke or anything internal really b/c I want to know before I buy it. I dont think homeboy who's selling it wants me tearing his engine down

 

btw. If it's an aluminum block with flat tops then it's an L33 5.3 HO

I edited my previous post for the pistons. Just pull a plug and shine a light in to look at the top of the piston.

 

It will say both on it, 5.3 and 4.8.

 

Damn so basically the only sure fire way to check is by pulling a plug and looking down at the piston?

 

Yes. the block says 4.8/5.3. you have to pull a plug and see if the piston is dished or flat. dished is 5.3 and flat is 4.8.

 

Not sure if you'll be able to see what you're looking for by just pulling a plug, as you may not be able to see the circumference of the pistons, might need a bore scope to get a good look...but as I mentioned, I"m not sure...

 

The exterior of both engines is exactly the same and even use the same heads. The only difference is the type of piston used and the stroke of the crank.

 

Bought the engine for $300. I tore the heads off b/c the guys put head gaskets on it and didnt replace the head bolts (and I just dont trust other people's work). Its definitely a 5.3 so Im happy with that but it had been sitting for a year + and there was slight surface rust on the sylinder walls. So Im pullin the whole thing apart and honing the cylinder walls before I put it back together.

I really appreciate the help guys! I started a new thread with some build questions if you don't mind helping there to ----> https://www.performancetrucks.net/fo...93#post4529493