351w

Those really good Ford guys should know, if they're really good Ford guys, there's no such thing as big or small block in Ford.

FE's, Y-blocks, FT's, 335's, 385's, MEL's, Windsor's...

All engine families, not inhibited by cubic inch size.

For example, the FE ran from 332 all the way up to 428 with a 427 in between.

Edit: let me correct myself. They "did" have big and small blocks. In inline six cylinders. The 200 was a small block, the 240 and 300's were big blocks.
The 300 six was in my opinion one of the best engines that ford ever built. I had one in a 4x4 ford truck. Had a set of headers on it, looked like a plate of spaghetti noodles. But man did that thing make gobs of just stump pulling power. I had a big *** lift kit and 36" mudders on there, I would wheel that truck everywhere. I'd load it up with firewood down excavator logging trails and power through the mud with a chain hooked up to big ol chevy 4x4s pulling them out of axle deep stuck mud all the way to the paved road. I miss that truck. I search craigslist for it regularly. If I ever see it again for sale i'll buy it right away.