Nice car with some interesting stuff...has a 6500rpm redline tach and an authentic looking build sheet that has the Z15 SS454 option written on the sheet by hand. Looks legit to me, since there are other typed codes on the build sheet that correspond to the LS5 option, just never seen any hand-written 'addendum' on a build sheet before (besides instructions for special paint, etc).
Link to 1970 Chevelle SS454 auction
136370A116932