what would it take to get 100mph

[swizzlestick]

Hello all. I'm not sure I've officially introduced myself even though I've been bothering you guys for years. My name's Chad and have a 49 3100 chevy. I started an s-10 swap but realize now I'd rather do a more traditional style truck with lowered original frame and running gear. so the question is can I get an era correct inline 6 and the three on the tree tranny to safely go 100mph(not that I need to go that fast but id like it if i could). would the trans have low enough gears to just hop-up the engine a little and put a high geared rear in it? how would they have done it back in the 50's? Thanks, Chad