tube chassis drag cars probably don't care all that much about steering geometry. And they're probably making thier own racks, or can source custom racks to suit specific purposes/fitments.

I'm talking about circuit racing chassis builders. I don't think you'll find too many spaceframe chassis circuit cars using anything other than rack and pinion. worm and recirculating ball steering boxes just don't cut it. these guys have experience in building cars from scratch and making them go around corners. If they say its not feasible - it isn't.

a dodgy backyard conversion from a bloke more interested in doing than talking (and presumably listening) is highly unlikely to be a very good installation. sure it might be fitted securely and actually turn the wheels, but physically making it fit and connecting it to the wheels isn't such a big trick, but there's alot more to it than that. things like bump steer and ackermann.