ok im assuming you understand how torsion springs work... the "spring pressure" is accually acheived from the twisting pressure on the torsion bar.
The ford keys on the chevy already creates more spring pressure and then by cranking the adjusting bolts up will increase this even more. Therefore raising the truck up, and also greatly increasing the spring pressure. Makes it so that the suspension has very little "up travel" and thus creating an uncomfortable ride... great look though
Now for the ford. I have not had first hand experience with this situation but if the effects are equaly as dramatic then you will acheive the look you are going for but will somehow sacrifice ride quality. i think.
I am VERY interested in how this works out though. keep us posted
good luck,
SouthernStyle