Funny thing, I was considering the same with my 300CE but I like more power with the same space taken. Talked with Scat who makes stroker cranks and they said no problem for the 4.3 taken out to 5.6 liters. Chevy 350s are taken out to 383" with a stroker and the 4.3 is 75% of a 350, so figure.
I also found some old Brodix Nascar Grand National heads when they ran V6s with intake valves like 2.125" Build it with good rods, forged pistons and put a supercharger on it for an easy 400hp!
In the meantime I'll have to suffice with my 190 with a Ford 5.0 in it....shortly to be 5.66!!
Glad to know there are other masochists in the world that play with cars. I look at it as saving it from being made into scrap iron and letting it live longer.
C280Sport, 300CE, 400E, 190/5.0