ly6 6.0 which transmission

[1981 chevy10blazer5]

ok guy i need a lil help on going which route with my truck i have a 81 stepside 4x4 and want a ly6 which as you know has ls3 heads im wanting to change the intake to give it a old school carb look but want to stay fuel injected so i was planing on buyin a holley mid rise intake so i could put on it a 4150 style thorttle body but my main concern is which transmission should i go with i have a 700r just needs a rebuild or buy a th400 could a 700r handle the power this truck is gonna be my daily driver amd every once in a blue give it a hell not to much though since it will be my daily has anyone had this conversion any pics or concern you guys had would be greatly appreciated