What is the difference between a CA77 and a CA78

[Izoomx2]

The engine number is ca77 e-318479 and the frame number is ca - 78 - 314624 from what I read here this bike was made late '63 - early '64 ? sound right?

[ELMST616]

Frame is CA78 - 1014749
Engine is CA77E - 1015105

From Bill Silvers restore guide i have read this was simply an odd change that occurred in 1964.

"Starting in 1964, the
badges had only HONDA 250 or HONDA 300 lettering. Honda considered the 305cc
models to be Model 300, even though the actual cc displacement of the engines were
305cc. 1964 saw an odd change in the chassis numbers, as most all 305cc Dreams were
marked CA78-XXXXXX, while the engines still bore CA77E-XXXXXX numbers"

[Ws50599]

I have a Honda 300 (tank #) with motor stamp CA77 101574. and frame stamp 101553. See pics.

[Ws50599]

The frame stamp is CA78. 101553

[Ws50599]

Here's my 1964 Honda 300 (tank) Dream vin on frame CA 78 101553. Motor CA 77 101574 see pics