Mine engine weighed somewhere in the 425-450 pounds shipped. But thats with Alumi. heads and intake.
As goes for what stroke...it's up to you really. You can open up a big debate over that very simple topic.
If your like me and want to keep things as simple as possiable, shift at a normal RPM range (5,600-6,200 rpms) I would go with at least a 408 if not a 418. If your going with a Dart block by ALL MEANS get the "Big Bore" option (4.125) instead of the standard bore (4.0).
4.030 Bore x 4.0 stroke is a 408 and use the 6.250 size rod.
4.125 Bore x 4.0 Stroke is a 427- 8 CI
or
4.030 Bore x 4.100 stroke is a 418
4.125 Bore x 4.100 Stroke is 436+ cubes. (i think)
Use the TFS-R heads out of the Box or a Set of AFR 225 heads out of the box.
Super Victor intake (out of the box)
750-825 Mighty Demon
or
850-950HP Holley
1 7/8 Kook Headers or 2.0 inch
10.5 to 1 compression
HYD roller Cam (Custom and in the 250+ range @.50 & .600 lift range)
Shifting in the 6,000 rpm range
Will net you a 575+ Horsepower, N/A ,Pump Gas Grocery Getter!
Will also set you back in some where around $10,000+ then add another 1,500-2,000 for the Dart Block option if you are considering it.
**remember anything over the 420 cubes will require some more work (porting) to the above list, due to the size of the motor.
Anything less then a 383 CI would most likely Require a Victor JR. intake but need alot of porting.
My .02's