can I modify a aftermarket fiberglass bolt on hood, to look right on a 71? a friend has it and I get it for trade, its a good one he paid like a grand for it but I don't know brand, its glass top and bottom uses hinges and the cool factory hood pins,

 

The 70 hood is significantly different from the 71, no can do unless you want to also change the grill and most of the rest of the nose of the car. Look at a 71 versus 70 front end closely in pictures. The 70 hood leading edge is straighter than the 71.

 

Hint: Google Images is your friend.





Short answer, not even close. The 71-72 grilles go up into the leading edge of the hood. Yeah, you can do it. It will either look like crap or you'll spend WAAAAAY more time and money than simply getting the correct hood.