I've got a 91 305 and I want to put in a dash from a 350. Mine has the 110 spedometer and the dash I want to replace it with has a 140 speedo. If I just pop the new dash in place, will it work, or will the needle for the spedometer be in the wrong place because the numbers don't line up in the same spot. What I mean is, on my 110 dash, when the needle's pointing straight up, it's at 70mph. In the straight-up position on the 140 dash, it'll be pointing at 90 mph. So I guess I'm asking will the needle adjust itself for the 140 dash, or will my spedometer be off? Please remember that 91s are electric, not cable driven.

 

Because your speedo is electronic, it is actually controlled by the ECM via the VSS. There is no unique VSS for the 91 F-bodies, they are all the same and the speedo gears are decided by your axle/tire combo only.

I cannot see GM having differnt "voltage requirements" for the different speedos and nothing in my shop manual suggests different voltage outputs for a given speed. So I believe you will not have any problems.

But, if you want to test it, just take the leads from your current speedo and put the wires into the new setup. Then take it to a road that has a measured mile, drive EXACTLY at 60 mph and time yourself. If it takes 60 seconds to travel the mile, then you are ok.

My bet is, it all works fine.

 

So long as you do not touch the drive/driven gears in your trans the VSS couldn't give a s**t. The speedo is the one that converts the pulse (elec)/rotory (cable) action to the correct position on the speedo. So if you (for example) have a 115 speedo and replace it with a 145 speedo, your gauges will read correctly.

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George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

[This message has been edited by MRZ28HO (edited October 12, 2000).]

 

Just remember to switch the circuit card that is attached to the speedo as well. Based on experience with my 90 Formula,I swapped the 120 cluster for a 140 from a 350 car. Their is a circuit card with the correct resistors,etc. that will allow it to work correctly. This is assuming the camaros had a similar setup.


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