16" vs. 15" bolt pattern

[Charles Chance]

Is the bolt pattern the same for the 515/416 16" frame the same as the 15"? I'm toying with the idea of replacing my 416A's with 515's (in 825 cabs) and if the bolt pattern is different, it will limit my selection. Thanks in advance for any responses.

[Jim Easley]

Charles,
I will send you a diagram. The bolt circle is a little different for 15" and 16" models however, most of the later 16" frames have slotted quarter inch mounting holes. If your original holes are on a 14 9/16" circle, you will be fine as this falls within the slotted area of the 16" bolt circle. The baffle cutouts for front or rear mounting however, are not the same.
Jim