Ladder frame chassis rigidity & engine movement?

[Ant]

I have the opportunity of running at least two braces in the cockpit area to try and strengthen the chassis, and missing the seats, as my chassis is similar to an original style!
I have a single hoop roll bar, back brace and long forward brace going down to the main chassis rail. Some cars have the doors not opening and also large forward braces off full hoop roll hoops.

The major problem is I think this detracts from the original design and makes them into like a Transam style race car, where as this car is for mainly road use, but I am thinking is a ladder frame that much of a disadvantage over a space frame, some space frames may be no stronger than this simple design when put to the test?

Also has anyone considered the need to fit off the RHS Head a brace with maybe urethane bushes to limit engine movement, my last cobra had turn buckles on the cast heads and was all solid mounted, not that greater idea for road! - as am running oval (under car) pipes under one area of the chassis through about 3.5" of space, but there is plenty of room for muffler.

Cheers Ant