Adapter Towers
If your engine was originally equipped with dinky 5mm spark plug wires you’ll find it tough to fit a new set of 8.5mm wires.
That is, unless you use a set of MSD Adapter Towers. These Adapters fit securely in the original cap while accepting the dual
crimp terminals of the MSD 8.5mm Wire!

Adapter Tower, set of 8
PN 8405