A sweater, called a 'jumper' in the UK, is a knit garment that is worn in place of, or over a shirt. The knitting can have many different types of patterns, both in the colors and the patterns. They...
It could be if it is a big block but a "long block" means it includes the heads a short block does not.
Because it is the last block to be filled.
right below the heads
The 351M, is "modified." Windsor motor, with Cleveleand heads. So, I guessd a small block.