69 speedo hole in firewall size?? (Muncie 4 speed)

[DT]

Anyone know what the size of the speedometer hole is on the firewall next to the wiper motor on 69 4 speed Muncie applications??

[bertfam]

Take a look at UPC 0, sheet A9 in the AIM and you'll see that the RPO M20 hole piercing for 8A is 1"

Ed

[DT]

Thank you very much Ed!!

[DT]

I'm wondering if I could get away with a 7/8's inch hole?? Anyone??

[bertfam]

Not if you're going to install an ORIGINAL STYLE GROMMET. It's a tight fit even at one inch!

Ed

[DT]

OK, thanks once again Ed!!