Well, since I want to be able to restore the '68 back to stock pretty
easily, what are my engine options? I've heard that the 351C/351W is a
drop-in for this car. I've also heard that a bigger (390, 429 and 460)
motor requires modification like moving the shock towers up front.

Is that true? How big a motor can I just drop in? How much work is it to
put a big block in?

Thanks!
Thomas