Still fairly new to the forum, so forgive me if I insult anyone with what will probably sound like a really DUMB question:

What are the different '01 Z-28's? and how do you tell the differences? For example, I noticed on some sign-off lines "LS1-A4". Aren't all '01 Z-28's LS-1's? and what does "A4" signify? and how do I determine what I've got?

All I knew when I test drove the Z-28 I have now back in Nov.2001 is that it impressed the hell out of me and I didn't even need to go test drive anything else. I didn't know about different styles, etc... I just knew I wanted it. So I bought it! Badda-bing, batta-boom... Done!

Thanks gang!
Daryl

 

The A-4 simply means you have an automatic transmission-4 speed.

 

I suspected it was that. Any differences in motors? I know there were options on rear ends, etc. There is a small white sticker on top of my fan shroud "347". I know that's the 5.7, but are there differences yet?
Daryl

 

Daryl,

All of the LS1's in the cars to date are the same size: 347 cid. GM did make some changes starting in the 2001 model year from the 1998-2000 LS1 f-bodies. Some of the changes include a new head casting that flows better out of the box (casting #241), LS6 intake manifold comes standard, no EGR system, and a smaller camshaft. GM tried to "tune down" the cars since they did get a better head casting and LS6 intake manifold, so they started using the camshaft out of the trucks. It's the same cam that they used in the '99 6.0L trucks and in all small-block V8 Chevy/GMC trucks starting in 2000. One was put on a cam doctor (measures exact specs of a camshaft), and it speced out to 192/190, .455"/.465", 115 LSA. It's VERY small! This is why you see such incredible gains swapping in a camshaft. I picked up just under 45 RWHP with our 224R camshaft!

As for rearend gear choices, the six-speed cars only came with 3.42:1 gearing. The auto-equipped cars came standard with 2.73:1 gears (unless it's a WS-6, SS, or Firehawk) and had 3.23:1 gears as the performance axle option (GU5). FYI, the only LS1's that did not receive an aluminum driveshaft from the factory were the 2.73:1-equipped autos. They received a steel driveshaft.

I hope this answers some of your questions.

Trevor
Texas Speed & Performance

 

You don't have a whole lot to worry about it terms of worse performance. The 2001 and 2002 z28s are generally a little more powerfull than before due to having the ls6 intake plus it has no egr(not sure if it effects performance). Yes you could have two different types of rear gears in an a4. I'm sure someone after me posting can tell you the codes on the side of your door for the different gears, you could have either 2.73 or 3.23 i beleive. As far as other options, there were different wheel packages, Im not sure if the z28 offered another suspension package in 2001 but it could have. These are the only performance options i can think of right now.

somone beat me to the post!