75 Firebird Tach Question

[Jack_Tar]

I have several instrument clusters that I was told fit a 75 Firebird. My question is what was the difference in the cars that had the 6k and 8k tachs?

[njsteve]

Can you post a photo? The 70-74 were the higher 8000 RPM tachs, I believe, and the speedo's went a lot higher as well. The speedo in my Gramma's 75 Firebird goes to 100 while the 73 goes to 160

[GTO_DON]

8000 tachs were used till 1976. the speedo went from 160 to 100 in 1975 Tachs were lowered to 6000 in 1977

[Jack_Tar]

It looks like these were 77 and later gauges that someone was going to put 8K tachs in.