My friend came across a motor for a truck with a magnuson supercahrger but the guy who owned it was not sure what motor it was. Would there be anyways to tell maybe from casting numbers or external differences? I know a t is a 5.3 liter and a z is a 4.8 liter but it doesnt have a vin number. Thanks guys. Claims to be out of a joe gibbs silverado. When i looked on line they came in both motor set ups? Any help would be nice

 

Here is a pic of it.
http://chevytruckworld.tenmagazines....l01/289433.jpg

 

351winsor

 

A 6.0 will have 035 or 317 casting cylinder heads and a 5.3/4.8 will have 862 or 706. To tell the difference between the 5.3 and 4.8 you will need to pull the oil pan to check the stroke of the crank(3.622 = 5.3/3.268 = 4.8) or pull the head off to check the piston(flat top = 4.8/dished = 5.3). You may be able to look in the spark plug hole and see the top of the piston. I have never tried it myself, but I have seen others recommend it.

 

As far as I know they only did the Joe Gibbs package on the 4.8 motors. This makes sense, since none of the rest of the drivetrain was upgraded. BTW, I don't know of any external way to tell a 4.8 from a 5.3.

 

I was pretty sure the Joe Gibbs trucks were all 4.8's too.

 

Cool, im going to pull off the super charger this weekend and start bolting up the intercooler and pump. If someone connects the ecm up to a computer would it give them the info of the motor? I think its going to be a 4.8 liter

 

i thought 5.3l or whatever was cast into the block in the back i'm sure my 5.7 is or it might be the front

 

It is but the 5.3 and 4.8 use the same block, so the back is stamped with 4.8/5.3. Plus I wasn't sure if he was trying to identify it with the tranny bolted up so I gave him the head casting numbers.