About the Tachs,Chuck Hansons 1970 L78 Convert came with 1969 SS36 Door panel emblems,and a 5500 redline tach.It was dated correctly too,but look at the whole car,not just one indicator.They were built by Humans after all.
That being said,after reading this ebay aucion,I don't believe it to be an LS5,or LS6 originally.
He picked the wrong Chevelle to Speculate that 454 claim on,as Canadian built Chevelles listed there RPO's on the cowl tag,and you can also run the VIN# through George Z. at Vinage Vehicle Services to find out is true Heritage.
I can see a few things wrong with the Chevelle in question.
*This Chevelles Cowl tag says it was built at Oshawa Ontario Plant.Oshawa Ontario Plant never Produced a 1970 LS6 Chevelle,...LS5's,yes.
*If the Seller would list the rearend suffix code and it was original to this Chevelle,that would tell us the original engine it was born with,if the authentic rearend.
*It's a November 2nd week built Chevelle,to early for LS6 anyway.
*Z25 is a 396 RPO,which the cowl tag is stating.Not a 454 engine,which would be RPO Z15.
*Showing a TH400 now,but cowl tag calls out for a Manual trans. M20 originally,and as Bill said,Not for an LS6.
I think this may be why the bidding is so low.
I do Like code 78 Black Cherry 1970 Chevelles,and would think it is a good canidate for a restoration if priced accordingly...
Rick