I'm not familiar with the front shocks on the 2wd Blazers. Have you looked at the shocks from different manufacturers to compare? Sometime a manufacturer will provide one replacement part for many applications that will not be exactly like the original. Oftentimes the replacement represents a later replacement for the original.

In particular though, I've never seen a shock with that extra disk unless perhaps it was intended to support a boot that would keep the shaft clean as it goes in and out of the body of the shock.

Otherwise, does it seem like it will work?

I search now there is no Aftermarket or OEM that manufacture it with this disk. I try to compress the shock by pressing it on the floor it seem already compress because it's not compress when I do that

here is a list of the parts

BILSTEIN 24187428
KYBKG5450
KYB565046
GABRIEL58421
ACDELCO52525
ACDELCO530156
MONROE37129
KYB344040

Thank you christine for reply

I know now how it's work but I don't it's normal or not. It extend when I pull it by hand and compressed when I push it.

It should extend by itself. If it doesn't, it sounds like there's no gas in them.