Looking to see if anyone has a lead on buying just a pcb for a 3/4 capacitor Pack. I am looking to build myself some cap packs for stock racing. Can I use a breakout board, wiring the capacitors in parallel, or do I have to use a pcb ? Any and all help is appreciated.

Normal capacitors have long enough legs, no need for a PCB....

I would then solder the positive legs together, then the negative. Use a liquid electrical tape, then heat shrink the assembly?

No electrical tape needed, if you keep the legs short they will never touch. Also why electrical tape, it is ugly and shrink wrap works much better.

But what do you think to expect from an own capacitor bank? A good capacitor bank can make a tiny difference in the hands of a good driver. For most it will not make a difference, for sure if you use average capacitors..

I plan on shrink wrapping the assembly, makes sense keeping the legs short enough. I want to try larger uF capacitors. I have 3 1800uF Panasonic I want to try in stock class, seeing R1 and Teampowers are always sold out on their cap packs. I believe I have a good amount of drop when I get on the throttle in high grip clay in my stock buggies, so I am hoping I will not see so much as a voltage drop as I get on the throttle. I expect I will see a better result on carpet as I am going to run a torquier rotor in my motor, seeing grip is up.

Appreciate the assistance.

Nope, A capacitor is on an ESC to filter the ripple on the power lines. Ripple can disturb the working of the FET's losing power put into heat. What you think that will happen with a high capacity will not happen. The internal resistance of your capacitor bank with plain electrolytic capacitors will not come close to the very low internal resistance of a good LiPo battery so it will not give you the boost everyone can talk about.

There is a topic here on this forum where we talked about these and where we made capacitor banks based on small SMD ceramic capacitors which are now a hype as "non-polarity capacitors". Ceramic capacitors react faster and together they will have a low resistance. In that topic also a guy who did measure with a scope on several configurations. I made about 50 capacitors based on ceramic ones. With just 900uF (9x 100uF) what is about a same value as the 2 capacitor banks with most ESC's and a good driver did only notice a better brake.

Thank you for the insight, I was working under the presumption of larger capacitor as reacting to the amp draw for the second I would have asa I punched the throttle. I was looking more for not loading the motor/esc. I see my presumption is incorrect. I run a Trinity white Lipo in both stock cars, battery wise I should be in the clear.

Some stuff to read:

Capacitors on speedos - R/C Tech Forums (rctech.net)

And the topic I mentioned:
Running a speedo without a capacitor? - R/C Tech Forums (rctech.net)