If your centring your engine to give more space where the steering box is, there is another alternative. I was sick and tired of not having access to the driver side of my motor, mirror image 77 RHD, so I opted to put in a rack and pinion system. Not cheap, around $2500 but worth every penny.
Revelation Racing Supplies at Brookvale did the work. Basically bolts in using the original steering box holes on the now passenger side and the now steering box holes on the now driver side.
The only change to engine mounting was that we had to fit 6mm spacers between the engine and engine mount so that the racks rubber boots would clear the sump. I don't have an original sump on the motor with the double step in it. If I did, no spacing would have been required.
The other thing I did was change the floor pan in the foot well to accommodate my big feet. I simply cut out the chamfered section and welded in a new piece so that the now driver side foot well is the same as the passenger side foot well. In this shot you can still see the fibre glass mould, to get the right shape, fitted just behind the left hand extractor/pipe flange. Much more foot room now. [A big thank you to Kym Burns for the idea]
On the welding side of things I'll think you'll find that tidy welding was NOT a thing that was High on Chev's list.
I'm still using my stock radiator re-cored and a flex fan. Won't know how it goes until she is on the road, but the bench test connected to the motor was fine.