couple of newbe questions

[mater69]

I have a 69 c10 ramp truck. It is currently sporting a 327 and 4 speed manual trans with 1 ton 8 lug running gear. I am wanting to swap in a 454, but am curious if I can still keep my 4 speed granny gear tranny. I don't know what kind or which model it is, I just know the gear ratios are really close, and it is really wound out at 60mph...I need to keep a manual trans. because of towing cars, etc. any help would be greatly appreciated.

oh yeah, oil pump failed today, and I locked it down, so a swap will commence shortly...