I have a '70 351c 2v. Looking at some ram air options, and it looks like that none sold in 1970 had it. The 302 did, as well as the 428/429s.
In 1971, the Mustang had a 351 4v ram air package, but only on the M and R codes I think. Not the 2v.
I found this: http://www.mustangsunlimited.com/ite...atKey=EMUSTANG
Think that'll fit on a 70 2v? I'm not terribly savy under the hood, so sorry if i'm coming across as a noob.