I am not sure whether "big block" and "small block" are terms that are capable of precise definition. As noted above, the 360 is part of the "FE" series of engines, which ranged from 332 to 428 cubic inches of displacement, with the 352, 390, 427 and 428 being the best known variants, and the 360 (a truck-only variant) being probably the most common V8 in 68-76 trucks.
The FE series is fully skirted, and it was the largest displacement V8 in the Ford lineup for most of its life. Throughout the 60s, your choices were generally the 289/302/351 cid "small block", or the 352/360/390/427/428 "FE", so the FE was generally referred to as a big block. In the very late 60s, however, Ford rolled out the "385 series", which was soon available in 429 and 460 cid versions. The 429/460 replaced the FE as the "big" V8 option in cars in the early 70s, and in trucks by the mid-70s (the FE was last offered in the 1976 truck line). Through the early 70s, therefore, Ford was offering two different "big blocks", the FE and the 385 series.