roller conversion can be had very cheap. lt1 cams can be found for super cheap also. im also running an lt1 cam in my 355 and had the lt4 cam in my 383 tbi.
my 355 goes like this
lt1 cam(free), lifters(10 bucks), valley girdle(included in the 10) i got off a friend, new timing chain cloyes(40) i believe it was, i have an old set of world torquer heads(traded a winshield for them backin the day) with 2.02 valves. edelbrock intake(200 including new throttle body that i needed and some other stuff), tbi mods(few bucks worth of pads), new valves, seals, spring, 1.5 roller tip rockers(all came with the heads) i think they are possibly 1.6, and my friend tuned me a chip(35 for aadapter free for the chip as he owes me). altogether i have no more than 300 bucks into my setup as i searched around asked friends, and already had bumped up compression. mine is sitting comfortably around 9.8:1 or close to that.
instead of doing a cam youd get alot more succes just working with your airflow to begin otherwise youll choke out the cam with the stock stuff. vortec heads would be great but youd have to switch manifolds. hell even a set of TPI 350 heads would be alot bnetter than ewhats currently on there, and i beleieve theres a pair on TGO right now. headers would improve exhasut flow. or if you have the budget do a complete overhaul. most of the stuff can be had cheap off of ebay/craigslist/local forums/thirdgen.org/ls1tech/places like that. even accomodating a cheap used engine you could maybe gather a few good components.
like woody said the lt1 cam on a 350-357 opens everything up alot while still making it easily tuneable, because with a cam swap you will need an updated chip to the mods you did. my 383 loved my lt4 cam but it was alot harder for my friend to tune, he had the chip back and forth about a dozen or so times until he finally got it perfect.
