I am trying to remember what I did 20 years ago. Some of this may be wrong so PLEASE double check. I put a 392 in a 41 Willys before the nostalgia craze. I used a 3/4 inch plate to space the tranny back and put the block dowel pins in it. The small block does mount closely but enough difference to cause head aches. I thought there was too much run out with my limited fab skills. I then bought a Wilcap version that was also 3/4 inch but it adapted a chev pattern and they had crank flange spacers. I recall that was the one that was used. And yes,a scatershield was used but no, lenkos are out of the budget. Hope this helps, cool looking ride!
PS I think Hot heads may sell the Wilcap line now.