Just curious because my 1991 Z28 350TPI has the 145mph.
I saw other (Z28's also) of the same year with 110's. I thought it was: Z28's--145mphspeedo RS--110mph speedo.
Did it have anything to do with whether it was a 350 or 305?

 

The Z28s with a 350 got the 145. The 305 Z28s had the 115.. The Z28 with a 305 and the 1LE package or the G92 package got the 145 but with a different yellow and red section on the RPM guage.

 

It's a long story:

https://www.thirdgen.org/techbb2/sho...&highlight=145

JamesC

 

phew...after reading all that, a question mark stills hovers above my head.

I assume then with my 91Z with the rpo codes B2L & G92 & L98 would be at least part of the reason for the 145.

 

I assume (and you know what that makes me) that 350's had the 140 along with the 5500 tach as standard equipment.

JamesC

 

What about the 85mph ones? i have an 86 iroc z28 and it only goes to 85

 

In the end, does the speedo you have make a difference? If so, swap it out--I went from an 85 to 140. I went with the "cool" factor.

JamesC

 

We need to remember one thing. No matter what is or was considered standard or optional, Dealers could order a car set up just like they want or for that much a person that pre pays for an unbuilt vehicle can get exactly the options he or she wants. There is a myth that no 350 5 speeds were ever produced. This is true to an extent. You could order a 350 5 speed if you wanted one, but it voided warrantly on the transmission. It was not a standard production offering. Also from 1990 -1992 a Z28 with T-tops was not available with the G92 option or a 5 speed, and was no longer available with the 350 as were the convertibles, BUT some dealers ordered some how they wanted and customers also. I have a '91 Z28 with a 305 that came with a 5 speed and the G92 option, but the previous owner special ordered the car like he wanted. You just have to pay upfront and wait a few weeks for your car.