Wow, you've got a beautiful '57 and I really like the look now. If you're set on changing it I like the lowered, no skirt look better - just my preference, but to me a hardtop (no post) compliments the line of skirts more than a post sedan. I believe that Dave (IC2) has given you very good advice about the Fordomatic tranny - I would think it would have a short life with any higher output crate engine.