Round to square headlights

[silverstude]

...or should I say round headlights in a 70 to the square type in an 85...

Is there a common bucket that can be used?

[mfg]

The headlamp mounting bucket for those large rectangular headlights, (as used on '85 Avanti), would be a boneyard item common to any vehicle which originally used them.....however, the fiberglass housing behind the bucket would have to be slightly modified on your '70 Avanti, and you'd also need to purchase the L&R bezels that surround these headlights (SI has those on sale this month!)