I just saw one of those $1200 GM crate motors dynoed the other day, and it made 259 hp with a small Holley. That motor is a smokin deal.
Something to think about is that a "rockcrusher" will bolt up to that motor/ bell housing and you probably will not even have to change the drive shaft for length or spline. I did this to a 63 chevy shorty that I had. I put a 327 in that truck, but I used the mounts out of another truck and the 6 bellhousing.
My 2 cents ....................................Larry