Factory tach & boost guage

[turbo t]

87 GN w/o digital dash. Tach reads off the scale and boost guage not working properly. I remember hearing of a fix but need refreshing. Thanks for any help.
Turbo T

[NOTACARLO]

I think Dennis Kirban has/sells a fix for that.

[PaCemkr86]

Caspers has what ya need

https://www.casperselectronics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=103070&Category_Code=8687GN_Perf

https://www.casperselectronics.com/Merchant2/images/103070-320.jpg