karkrazy1971

Can someone explain to me how I tell if my LT4 came with the z51 package? I tried the VIN decoder on this site and it doesn't say.

WVZR-1

Does the SPID label have Z51 on it? I guess you don't know or you wouldn't be asking but the SPID label with all of the RPO's would be in the rear storage compartment. If the SPID label is missing then take your VIN to a GM parts dept and ask that they print you an RPO list for your VIN. I'd think they would accommodate you.

karkrazy1971

I do believe it is in the rear compartment. I'll look and see what it says. Thanks for the the information. Just got the car and trying to decode what I got.

WVZR-1

It's all on the label! Take a snapshot of it and sit down with your computer.

This is generally considered to be a very accurate C4 RPO decoder. It's not what I use but it should be very helpful:

http://www.corvetteactioncenter.com/...o/8496rpo.html

c4cruiser

A quick clue would be to look at the wheels and tires. The standard coupe with Z51 got 275/40-17 tires and 17x9.5" 5-spoke ZR-1 style wheels on all 4 corners. Of course it's possible that a previous owner may have upgraded the tires and wheels.

WVZR-1

If the tire placard is still on the drivers door the information would be there also but the OP mentioned the SPID label presence so he should be all set. It seemed that he likely would have "more" questions so I thought the SPID label likely the best answer or the dealer visit. Tire placards are sometimes not there.

I don't believe that Z51 got 5-spokes except on the appropriate cars, GS and CE specifically.

karkrazy1971

Thanks guys. I'm going to run out on my break and see what I have. It has the saw blade wheels so it might be a base Corvette.

WVZR-1

I don't believe that Z51 got 5 spokes except on the appropriate cars. Z51 on a non-GS or CE car I believe would have saw-blades. Check the tire placard and the tire sizes maybe as well as the SPID label.

karkrazy1971

I'll check when I go on break and post up what I find. I'm anxious to see what it says. Either way, the car handles great.

karkrazy1971

Checked the tires and the RPO codes. Both confirm it's not the Z51 package. Guess what I need to do now is create a future plan to upgrade the suspension. I wonder if CoilOvers would suffice? I plan to do some autocross events throughout the next Summer.