I already run a 205 t-stat in all my magnum powered trucks, I can't find any higher.

The rod stroke ratio is over 1.85 in a 318, the 5.7 is just over 1.74, to match the 318 it would need about 3.35 stroke witch is too much to gain (lose?) from offset grinding and using stock bearing undersizes so then I need different rods probably a chevy 2.0 size, then custom pistons and balancing. I have a set of 6.25" 2.1" journal chevy rods (I think there are bearings to use with a 2.0 journal in these larger rods) but it would still need custom pistons balancing and the machine work to destroke it and I should probably buy a steel 6.1 crank to replace the 5.7 cast crank if turning it down that much.

Like I said I could easily build a late 5.7 with early 5.7 pistons with stuff I have laying around, it would be very easy to fine tune a tight quench (around .030) and very high compression (12.5ish) as the pistons are taller and have a larger dome and MDS would be sweet for this also so the actual engine it'self would be the easy part, the rotating mass is waaaay lighter than an old 318... I really would love to run a new hemi but man the installation kit stuff is very expensive, $900 headers, $150, motor mounts, $2000+ engine control, custom AC lines, PS lines, coolant hoses... and so far nobody has volunteered parts or money, sticking with the magnum I can re-use a ton of stuff.