Eric;
One thing that pops right out in your pictures is how high your distributor sits in your engine. MSD makes a short one designed for the 351W that will give you plenty of room for a drop-base filter. I couldn't find the receipt for mine, but the part# has 5 digits instead of the usual 4, so that's some help. Also, I looked at
oil sumps for Dart blocks and didn't like what I found, so I bought a marine-type pan from Armando's. No kick-outs or humps, just one shallow depth from front to rear and it holds 8 quarts, plus it was cheaper than the Canton pans. I hope this helps.
Bill