I don't beleive they'll even clear the shock towers. If you want a good shorty, I'd recommend JBA's. The JBA's on my son's '66 have been used daily for 3 years and still look great. They fit without any modifications and are the best made headers I've ever owned (and I've owned a few /forums/images/icons/wink.gif).
Otherwise, I'd go full length. I've never been fond of Tri-Y's, and the one set that I attempted to use were the worst fitting headers I've ever had ... took them back and traded them in on the JBA's, as they were going to take way too much bending to clear the C4 tranny.