what engine could make the most hp & lb-ft, cause the least amount of problems, and which would be least expensive.  

There's no clear cut answer to this question. The three thigns you're asking kind of fight each other.

The cheapest engine to build is gonna be the 350. The 350 and 383 will cause the least amount of problems (if built properly).

What kind of car do you need a motor for? What do you want the car to do?  

the car is a 91 caprice and I want the car to smoke anything that comes up to it at the light  

thats an easy one. put in an ls9 out of the corvette zr1! j/k really though, the 383 is going to be the best bet, b/c its basically a hybrid of the 350 and 400, and the parts are minutely more than those of the 350. thats how id go with my s10 if i hadn't of been so stubburn and put my 305 in. good thing on that is that i only have 200 bucks in it. once again, go with the 383 and good luck to ya!  

ya wanna smoke anything that comes to the light?

NITROUS, a good converter and 4.10s to get that boat goin!!

its not a ride without oxide!!!  

Thanks  

this is a street car not a track car and nitro destroys engine blocks and I also feel that nitro is a cheat move because if you beat another car off your motor alone you'll way better than having that thought in your mind that he or she almost beat you until you hit that button but thanks for your comment though especially the gear numbers and the converter