13 sec. 360 for $3,000?

just off some back of the barroom napkin maths, if there's machine work involved you're likely exceeding that 3K threshold

a cheap converter is gonna run you at least 500
then you're looking at around 400 cam & lifters
throw another 250 at that for a timing chain, valve springs & locks

add another 250 for incidentals and you're near half your budget.

it really, really depends on what you've got holding down the shop floor and stashed away on the shelves collecting dust. ignition, bearings, gaskets and a carb are all good things to have but they don't make power...

you need compression, heads that flow, and a cromulent induction system.

but, i'm guess you probably only need about 350hp to get to that magic mid 13's and with a 360 there's a lot of ways to cut that pie.