The early Pacific trucks in this era (May 1947 to March 1954) were assigned a model designation based upon the model of the rear-ends installed in the truck. Knowing the model of the truck can give an indication of the rear ends originally supplied with the truck.

Presumably due to the origins of Pacific Truck and Trailer being tightly tied to the Hayes Mfg. Co. (read more in the history page) the new founders showed their gratitude and appreciation of their roots by using a coded model designation based upon the rear ends installed in the truck and the name of their previous employer Hayes Mfg. Co.

During this era the model designation was a combination of letters and numbers, these numbers may be substituded for the letters in the phrase Hayes Mfg Co. The letters in the phrase were assigned the numbers 1 (H) through to 0 (g), two additional letters (D and W) also appear in these early model designations but do not have a number assigned to them.

As an example, the model EMAD used SF 462D rear ends, ignoring the initial letters SF and the final D, the letters EMA are the 4^th, 6^th and 2^nd digits in the phrase Hayes Mfg Co, the D in EMOD is used to differentiate between the SD & SFD (D prefix) and SW ( W prefix) axle option designations for the axles supplied with the truck.

During this era the coding as previously discussed was dropped for something a little less convoluted. While a model designation was still applied to the trucks based upon the rear-ends used in the truck the naming used was the model of the rear-ends, at sometimes simplified. As an exmple S. McKenzie's 1964 SRDD-D utilized model SRDD-D rear ends.

Following the release of the P9 in 1965 the model designations on Pacific trucks was once again changed. The P denoted Pacific and the letters following described the nominal height of the truck's frame rail. For instance the P9 was built with a 9" tall frame, the P10 a 10" tall frame an so on. Things did get a bit more complicated with models like the P12W, P12W-3 and most notably the P500.

With the release of the P500 in mid. 1974 replacing the P9 the model designation became a bit modified; while the P10, P12, P14 and P16 were still offered for sale, the P500 took the place of Pacific's on / off highway truck from the P9. The P500 was available with various frame heights (10" and 12") along with various front clip configurations. THe P500 model is expanded upon below.

This model featured the in house designed and built Pacific cab and was only available with a steel butterfly hood and steel fenders.

Looking at the dividing strip on the front window, note a formed steel centre post and two distincly separate front window panes. All four corners of both front window panes are radiused. The top edge of the front window panes is slightly higher than the top of the doors. Moving to the rear of the cab, the rear corners do not have a smooth radius, rahter this section of the cab is finished with a chamfered corner.

During the International Harvester years (years) the P500 model was available with a modified International PayStar cab, this model was available with a fibreglass hood or a steel front clip.

Looking at the dividing strip on the front window, note an absence of the formed steel centre post as seen in the P500P model, in its place is a single rubber seal utilized for the both the left and right window panes. On this cab, only the outside corners of both front window panes are radiused while the inside corners are square. The top edge of the front window panes is roughly in line with the of the doors. Moving to the rear of the cab, the rear corners are finished with a smooth radius.

The F designated a truck with the tilting fibreglass hood, while the S designated a truck with steel front clip.

Following the International Harvester years the P500 model was redesigned with a Pacific built cab, this model was available with a fibreglass hood or a steel front clip.

Looking at the dividing strip on the front window, the dividing strip is now a separate piece of formed steel which is bolted to the inner structure of the cab. From afar there appears to be no seal at the meeting point of the front window. On this cab, only the outside corners of both front window panes are radiused while the inside corners are square. The top edge of the front window panes is slightly higher than the top of the doors. Moving to the rear of the cab, the rear corners do not have a smooth radius, rahter this section of the cab is finished with a chamfered corner.

The PF designated a truck with the tilting fibreglass hood, while the PS designated a truck with steel front clip.