Looking for speaker recommendations for '74 Sport's (Jerry) speaker brackets

Glad to help.. 340Dilley asked me a question I couldn't answer. If someone else can I'm sure it would help everyone.. The Infinities I bought came with capacitors, I didn 't use mine (didn't know how to connect them) but if someone else could jump in and explain why you need them and how to connect, we all would benefit..
Thanks
19..