Any 306 running in the 11's N/A

check out fordmuscle.com. they did it in there 67 coupe t5.

of couse that was with a solid roller cam, not too big, something like 228/236, with a pump gas friendly motor, single plane intake, windsor Sr. heads.

I wouldn't say it's easy, took them quite a while to break 11's but it can be done, still isn't really a very streatable motor but you'd have to expect that.