Cubs have drag port timings. You can detune them...but you're detuning the nature of the beast.
How about a 4 mil cheetah motor with a power valve...if you're looking for more power and a duner...this is a better setup.
I can get you a complete motor built, depending on your budget. Can set it up for gas, alky, override, stock tranny, lockup, pretty cases, ugly cases....big carbs, small carbs.
Let's start with your budget, what do you want to spend...that will dictate what kind of motor you'll get.
I can customize the motor from add your own stuff to ready to bolt in and fire in your frame with your pipes.
Let me know.