You will need to take into account where the steering shaft will be located, assuming that the Mustang front end is rack and pinion. Headers don't always cooperate with that aspect, but ram horn manifolds shouldn't interfere. You may need to use either two left side or to two right side ram horn manifolds (I don't recall which). They need to both exit straight down to clear everything below.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
I did rams horn manifolds on my SBC in my 50 3600 (I bellieve the front part of the frame is the same) but I do not have the front suspension conversion that you have.
My rams horn manifolds just clear the top frame flange on both sides so no opportunity to shift the engine side to side.
The exhaust shop had to made some pretty tight bends to get the downward facing pipes at the manifolds turned to get over the frame cross brace. In retrospect a rear discharge manifold setup may have been easier to run the exhaust.
I did need to relocate my steering gear but again mine is stock so a different situation than you have.
My truck had a V8 in it when I got it. The steering box was moved 2 inches over which made the tire on the left rub if you turned the wheel hard to the left. Had to make a few changes.
I did a pre-purchase inspection of a 1951 3100 with a small block V8 and a M-II front suspension for a potential purchaser in France. The asking price was $75K, so it was a VERY fancy resto-mod. The steering shaft tried to lock up every half turn of the wheel due to some radical angles between the fancy IDIDIT steering column and the rack & pinion, due to some sharp angles the U joints in the steering shaft made. Obviously, I included that in my report, and I believe the buyer backed out of the deal. It's possible to do it right, but a LOT of people have no clue how to route the steering shaft. Do your homework, and have a basic understanding of geometry before committing to a installation! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
1955 Series 1 - I also moved my drag link inboard of the pitman arm to have the drag link as in-line and level as possible to minimize bump steer, etc.
As Hotrod Lincoln says - the steering geometry and how the ssytem works over the full range of both steering turn and suspension range are critical to having a drivable machine when you are done.