how to identify motor size 4.8-5.3

[G-BUDDY]

so i found a great motor for very cheap the prob is the guy doesnt know if its a 4.8 or 5.3 so my question is how do i identify the eng size? is there a website with this info? should there be a stamp on the back of the block ? i want to pick it up 2mrw for sure but just want to make sure on the size thanks for all the help ....this site ROCKS \/

 

[LT1_Malibu]

From what I read on the interwebs the info is stamped on the head gasket tab that's exposed. It should say either 4.8 or 5.3.

 

[z28krazy]

so i found a great motor for very cheap the prob is the guy doesnt know if its a 4.8 or 5.3 so my question is how do i identify the eng size? is there a website with this info? should there be a stamp on the back of the block ? i want to pick it up 2mrw for sure but just want to make sure on the size thanks for all the help ....this site ROCKS \/

Supposedly, these engines have the metric displacement (4.8L, 5.3L, 6.0L) cast on the passenger side rear of the block. Some also have the size cast on the side of the block near the freeze plugs. I've never looked at one, so take that for what it's worth.

If you look at the pad on the passenger side of the block, you might even find part of the vehicle VIN ID there. The older gen SBs had a three letter code that told you what year it was and what it was used for, unless it was an over the counter dealer replacement engine. Don't know if that's the case with the new gen blocks.

 

[boostinmalibu]

If you can't find any info on the numbers and such, pretty much the only other way is to pull a head. 4.8s had flat tops and 5.3s had dished pistons. I'd buy it at 4.8 price just to cover your *ss though.

 

[Tig]

Should be casted in either 4.8 or 5.3 like z28 said "on the passenger side rear of the block"

 

[boostinmalibu]

The 4.8s and 5.3s shared the same block, only difference is the stroke and piston.

 

[v8power]

The 4.8s and 5.3s shared the same block, only difference is the stroke and piston.

Right it will say 4.8/5.3 on the block. Only way is to pull a head, or get a bore scope down there

 

[kyhunter89]

some 5.3 came factory with flattops as well...

the crank is the only difference

 

[D&A Machine Shop]

Crank and rods are the difference. Even if its a 4.8 you can make a 5.3 by changing the crank and rods, or you can make a 5.7 by boring it and changing crank rods and pistons, you could go as big as 383 with the 4in stroker kit and the 5.7 bore.
If you are looking for a core to build then it will be an easy base to start with.