Thanks for the responses; seems either will work. Obviously there must be some difference between them. Still wondering about height (arch) & ride quality differences.
This will be a footbrake car at the track; has a 3500-stall converter (haven't verified actual stall yet), 3.91s (may change to 3.55s) and it'll be short-shifted to keep it above 11.50s...until the greed sets in... After the spring switch comes a tire decision, pretty tight with 275s, even with springs moved in 3/4". No room for additional clamps at the front sections. I don't think it'll hit the tire like a 4-speed or my 10-sec, 6,000-stall converter car does, but I could be wrong, as this thing makes gobs of torque.