I think that the engines all set in the same distance because if you look at the spacing from the firewall there the same, I believe more space was added on the front of the engine when they came out with the 390 engine. the 57, 58 & 59 engine bay was probably designed for the Y-block and the early FE block was made to fit in that space & in 1960 they added more room to the front of the engine for the accessories anyway that is my take on the subject.
I installed a 1966 Thunderbird 428 with the C6 transmission in my 58 Skyliner and I had to redo the mounting brackets on the radiator to get enough clearance even with the short water pump.