ok the is a number made into my block on the pass side on head side of block. right below the head cast number. its 25L04 or 25lo4 or25104. anybody have an idea what it means? i saw a tread that called it a block number but it did not list anything to say what it ment. also if the block is black its iron right?

 

Yeah, black is iron. There have been so many things changed on your engine it will be impossible to tell what it is by looking at it. I would say the easiest way to find out is to see if you can figure out who the tuner was, and they can tell you. Or if you know someone with the ability to check on your tune to see what it is. It might even be worth it to get a tune from one of the sponsors. The other way is to pull a cylinder head and measure. I know that doesn't really help much at all, and it isn't what you wanted to hear, but that is all I can think of.

 

no thats great. any info i can get helps alot. thanks

 

Actually, after thinking about it, you could measure from dropping the pan too. That would be much easier than the head. You can do that while it is still in the frame rails, and you can re-use that gasket too.

 

Take off the driverside Idler arm and see if it's stamped 4.8/5.3 or 6.0. Then use a borescope to look to see if it has Dish or Flat top pistons.
Flat top 4.8
Dish 5.3
Flat top LQ9 6.0
Dish LQ4 6.0

 

drop pan, check for stamped number on crank.