Folks,
Regarding the balancer issue for stroker motors.... Back when I was interested in a small block, and when I was about to use the JTR setup, I wanted to get a 383 or 406 with 8" Balancer. Concerned about the steering rack clearance issue, I e-mailed Mike Knell of JTR. He said to either 1) get the crank internally balanced, or 2) get the smaller 6" balancer (just make sure it has the 400-crank counterweight).
For those of you in the Los Angeles area, last year I ran into a guy at the Orange County Z club with a '73 240 Z with a 383 stroker. He had his crank balanced internally (with 5.7 350-type rods and stroker pistons).
Also, have we entirely ruled out the possibility to move the motor yet further back, clearing the steering rack entirely? If you're willing to ditch the stock hood latch location entirely, and relocate the brake and clutch hydraulic lines, there's got to be another inch of setback room lurking back there....