Welcome to the Stovebolt.
Foregive me for responding with attitude, but the first thing it takes is a 302, 5-speed and the appropriate stuff to go behind...
On a more serious note, if you are choosing a Chevy 302 and 5-speed that suggests a high revving performance approach. So you want a lower geared rear and running gear strong enough to support some serioius speed?
A frame swap will never be as easy as slide right under, but the S-10 is probably as close as you will get. You don't say what model truck yours is, so I don't know wheelbase. S-10s come in three or four different lengths. Changing the length of the S-10 or perhaps of the pickup bed, are both ways to can deal with a difference, but that's different than just slide in.
Tell us a little more about what you want to accomplish and maybe others will share more ideas.
