Need help with converter

Hi, i want to change my converter as recommended in an other thread. I have a offer by PTC. PTC wrote me this: "We offer a 9.5" street strip converter for this combo. It will flash around 3000 to 3500 rpm's. It is a direct replacement converter. We run 7/16 x 20 holes in our billet front. You may have to drill flexplate holes."
Questions: What flexplate do i have now in my stock car (what holes?)? Is it a good idea to drill holes yourself? What flexplate could i use with the PTC converter without drilling holes?

Here my combo:
72 Dodge Demon, 3350 lbs, Stock 1972 LA 318, A904, Stock heads, Stock 2bbl intake with Carter BBD (i may change to Edelbrock Performer 2176 and Edelbrock 650 AVS), Stock cam, TTI headers to Dual exhaust 2.5“, 8.75 axle with suregrip 3.91 ratio.

I only drive on the streets, no track. With the stock converter i’m not happy. The car is a dog off the line. I want to have a quick acceleration in a optimal torque curve with the new converter.
Thanks, Etor