84 Interstate speedo/tach conversion

[crowesnest3]

....idle minds would like to know. Can the speedo/tach on an 84 Interstate be swapped out to a say 83 speedo/tach ( 150 mph model )? Yes, I know one is rectangular the other round and that is the point .... would require fabricating a new dash panel ( like walnut burl?) the question is will they swap, will the drives interchange? Winter entertainment in the shop? .......... crowe....... :Egyptian:

 

[joedrum]

i dont think so

 

[backlander]

83 uses 18 in front wheel, 84 uses a 16 in front so the drives would be different.