im still gonna vote BB, things like trans, rad, would need to be upgraded anyways if you built up a smallblock.
I've been building on a 340 for a decade, as you can see in my sig. its a hot runner for a street car, but im on my 3rd camshaft, 2nd set of heads, 2nd trans, 2nd rad....etc...etc...basically everything i had when i started has been replaced be upgraded components to keep up with the motor..withthe exception of the crank/rods and pistons.
And guess what? I still want to go faster (its natural to feel that way)
Truth is, had i started with a BB i would have spent less, and most likely my car would be faster today.
Last summer i picked up a virgin 400 bb off a member here and with it came all acc. brackets etc. heck, he even threw in a 727 core for me.
what i paid was very similar to what i woulda paid for a smallblock core...and in the end i'll have much more motor (500"ci) which will put my current 340 in the dust, and 95% of the 408" motors in my taillights as well. i figure all said and done, this is gonna cost me the same as what i spent on the small block over the years, after all my parts swapping tryin to go faster.
The Moral of the story is to not fool yerself with what you want and what you are building. When i built my car it was a daily driver, which ended in its 2nd year as it was too much stress to park outside at the mall etc.. then again, had i built a 500"ci motor off the bat...i might not be here today writing this...so just be honest with yourself, a 400hp motor in a 4000lb car isnt exactly gonna put a hurt on any newer gt stang, and you will most likely will be lookin at the new challengers taillights should the occasion happen to arise....
Just something thats fast enough to turn some heads and put down some rubber, that is until my budget gets a little bigger! hehe! Then it'll be all out..but for now I'd be real happy to be pushin 350-400 hp...but of course thats never really good enough. But the highest speeds it would be seein for cuising would be 60-65 mph, maybe 10 miles distance at a time.
I have never heard any one disapointed with a big inch small block. They make great power especially for there size, when combined with a 904 they can knocks at least 200 lbs off a BB and that can make a big differance in the way a car drives. A 500 BB needs aftermarket heads or it won't be any faster than a stroker SB. Stock Magnum heads flow as much as a stock BB head and have WAY better chambers, wet flow, swirl, and velocity. Even the open chamber LA heads flow almost the same as a stock BB head.