Rack and Pinion vs engine setback for header clearance?

I've been eyeballing, measuring, and brainstorming for this engine swap. Early(1957) 392 hemi into a 66 dart with SB 727, anicipated HP maybe 450, torque maybe 500+ftlbs?(stock 392 hp=325 torque=430 so this would be a comparitivley mild hemi) One of the major hurdles will be header clearance. Looks to me like the left block hugger shorty header will hit the steering box. Its gelling in my head that there are 3 approaches to this problem.

1) set the engine back(and maybe up) until the downtubes clear the box. This means moving the firewall back oh maybe 4 inches or so. Also means the trans mount may be problematic. Ok a new or modified lower cross member could be fabricated. But I wonder if the torsion bar crossmember that goes 'over' the trans will restrict how high or back the 727 can fit in the tunnel because now the crossmember may be over the bulkier maincase instead of the slimmer tailshaft. I don't think I'm confident enough to start chopping up the torsion bar mounts. Oil pan mods are likely but maybe not overly complicated. Possibly a front sump?

2) swapping to a rack and pinion will eliminate the steering box problem and therefor maybe no engine setback at all, or maybe just a smidge. . I see its been done a lot but my concern would be what could happen in a catastrophic failure. Looks like the K frame has to be cut or notched to make the rack fit and this is a heavy engine (apx 750 lbs.. a good 250lbs over the /6 weight) plus a whole lot more torque. Will the K frame strength be compromised enough to cause serious problems? I've read bump steer can be a problem with converting to a rack. Anybody done a big block swap AND rack and pinion?

3) Ditch the headers and just go with stock, cast iron exhaust manifolds, which I also have on hand. Will still be a shoehorn job but will fit with mount spacers etc. Its been done. Possible engine setback about 1-2 inches? This puts the engine just about stock location so transmount should not be a BIG deal. I have a center sump pan that may work directly or with minimal mods. I'm reasonably sure I have a dropped centerlink but if not one could be gotten. BUT, I have the headers and it'd be shame not to use them, That'd be like throwing horsepower away? But at what cost? All those mods mentioned above?

Boils down to either go with a safer(?) outcome by setting back at the expense of ALOT of work...or have a potential risk by cutting up the kframe but the job should be alot simpler, overall...or keep it simple stupid and go with cast iron manifolds at the cost of power.

This will be a street car mostly. Dependability, durability and safety are major factors. But its still a hotrod, if you know what I mean.

I am so glad I have all you guys to bounce ideas off of. All my hotrodding friends from the old days have moved away. So any who want to weigh in with facts, figures or even conjecture..I'm all ears.

Once I actually start work I'll start a new thread for posterity, but for now short threads on particular subjects might work better for getting the input I need?

thanks much