dumb question
 

I'm only new to the world of cars so i'm allowed a few dumb questions, so heres the first i have got a 93 lacer cc coupe and i am in the process of doin it up(exterior) and soon shall be on to the engine, now i've been looking reading about and from what i can deduct the best motor seems to be the 4G63T, but upon lookin around to price one i could only find a 4G63BT engine now is there any differnce between the two or is it still sutiable for the conversion?