A 340 Tach question....

Hey all you "electrics" guys in the audience....

my 68 340 4 speed fastback formula s restoration is continuing.... i recently got my hands on an original nos 68 tach. because of the price of nos parts now, i'm a little afraid to actually put this tach in and hook it up. the fish currently has a 71 340 with an electronic ignition/distributor. do you guys know if it is safe to hook up an original 68 tach to an electronic ignition??? the last thing i want to do is fry this pristine museuem piece of a tach. do you think it would be better to save this nos item and buy one of those reproduction new tachs????

and here's the really embarrassing question... exactly how do you hook up a tach to an electronic ignition???

any help/comments would be greatly appreciated..

jim coster, pittsburgh