Switchbox Question (slight difference in model #'s)

[gidds]

Can anyone tell me what the difference is between the following switchbox model numbers:

Are they interchangable?

Thanks

332-2986A22 and the 332-2986A4

 

[Laddies]

Re: Switchbox Question (slight difference in model #'s)

The A4 box was the original part for a 6 cyl and is replaced by a A21 box, the A22 was a preplacement for the A6 box off a 4cyl, they are interchangeable today because the original boxes included a tach sender and it is not used today and that was the only differance