I vote for going all the way to the fenders. Do the entire top of the cowl.
Here's a link to a thread about T/A blackouts.
https://board.moparts.org/ubbthreads/show...&PHPSESSID=Do your cowl like that, but don't blackout anything on the fenders under the hood unless you're doing a T/A.
If I remember correctly, The T/A & AAR cowl blackout was sprayed before body color then masked off, and could be either organisol or regular blackout paint.
Other 70 E bodies would have the blackout sprayed after body color, same time as other blackouts, and would be regular blackout paint, not organisol.
The last 2 or 3 months of 70 production had cowl blackout cancelled, so E bodies after that shouldn't have it.
hope that helps.
Tav