Thread: 355 sbc question about exhaust sound (need some help here!)

Tweet

Tie, the numbers on the back of the block are big, ~3/8" tall in a string 2.5" to 3" long towards the back of the block. No one is saying that they are easy to see - you may need a telescoping mirror and a good bright flashlight to read them, and they may be covered over in grime. The casting number is generally biased to the drivers side off of center, but on some crate engines it's biased to the passenger side, just off center. You may end up laying atop the engine to get the angle to see them.

My ZZ4 has Made in Mexico and GM 5.7L on the drivers side, and 10243880 off center towards the passenger side, seen easiest from just above the right rocker cover rear. The pad up front is stamped ZZ4. You can read the casting numbers if you want to bad enough, but it may not be that big of a deal for you. The suffix number up front could have been machined away if the block was decked.

As for taking the engine into the 7000 plus rpm range, you'd probably be fine, but for me I'd want to know what's inside before I went much above 5000 to 5500. You can build a SBC to turn 10K, but pushing one too far without knowing what you've got is a crap shoot at best.