So you're thinking have the rack rigid to the frame and attach to each wheel?
That sounds like a poor idea to me, and more than likely unsafe. The toe in will be continually changing.

If you only attach one end and use a tie rod as original then I still think you'll have bump steer pretty bad.

So far I'm not a fan of rack and pinion on a straight axle either.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-