351 is great. It has gobs and gobs of torque. It's quick with 2.73 gears.
I never really tallied the cost. It's something that my wife and I don't discuss.
I went all out and got everything at once when my 302 was giving up the ghost. I'd say there's about $4000 in the engine, though. I also got a Tremec 3550 and King Cobra clutch about the same time. The clutch didn't last too long, so I upgraded it to a Centerforce.
------------------
351W 89 Mustang GT Convertible