savage x brushless conversion help

[savagehaley14]

what do i need to finish my conversion i have a savage roller with everything except the brushless stuff i have a 9920 esc how many cells can i safely run with an 8xl? i want to use my mechanical brake and 2-speed. (i think) i want to run an 8xl on 14 cells how fast will it go what gearing should i use for a top speed of 40 mph? what batterys should i use (nimh's preferably lipo's are out of the budget for a 15 year old) i will be able to make my own motor mount and battery holders but where do i get a clutchbell for a brushless motor and what brand motors should i use for something under 100 dollars any help will be greatly appreciated i will post pics when im done i dont get a lot of money and i have to build up my 1:1 car too so it will probably be awhile before its running