Recommendations bottom end

Hey guys,
I Have a 78 LT Camaro and want this old girl to perform. Ive looked at all the engine build up sites ect and have lots of good ideas, but what I want is a 78 350 that hauls ass. Now Ive already rebuilt the top end, but it didnt make the difference im after, the top end is currently a set of 64cc large valve pro topline heads, manifold is a holley contender with a 750 holley double pumper, cam is a performance crow comp 212-12-2 which has lift of .48 and .48, also runs yella terra roller rockers, and performance HEI dizzy, Ive spent about $2500 so far just on the top end. Now the car runs on gas so compression is not an issue, Im about to purchase a 350 block because the current block is a 327, the current block is still going strong and runs flat tops but I just cant seem to get it to perform like I want it to so hence the rebuild of a new block, now with rebuilding the bottom end I was thinking of going down the path of a stroked 350 to 383 with flat tops, is this worth the expense or should I just do a 350 with quality parts and decent compression. I want to keep all of the existing upper assembly as its probably got less than 5000 miles on it. Or am I barking up the wrong tree should this current setup with the 327 perform better, Any one got some good ideas, this is a daily driver and I do about 80 miles a day in her
Thanks Steve

If you are going to build a 350, it won't cost much more to build a 383, and you will notice a huge difference in torque. Yes, it is well worth the added expense. You will have to invest in a crankshaft and pistons. You can use the 5.7 350 connecting rods as long as you upgrade the rod bolts with ARP bolts. There will be additional expense with balancing the rotating assembly and machining the block. Your heads' combustion chamber size is a problem but you could easily sell them and get larger chambers so you can keep your compression level down, but you can use your intake manifold, carburetor and accessory brackets. A mildly built 383 can easily put out over 400 ft.lbs of torque, and that would give your car real kick in the pants power. My 383 runs your cam with AFR 190 heads and it makes 450 hp, and is easily street drivable.

Try changing the carb to a 670 vaccum secondiares, and change your rear gears to a set of 373's or 390's.
I think you will get a big change in acceleration, and performance.

Steve, here's a pretty good list of small block Chevys that have been dynoed and the results published in various mags. Look through the list and see if you can find the characteristics you are looking for and just plug in the parts from that build. Pretty simple, heh?
http://www.ryanscarpage.50megs.com/combos1.html

Thanks guys, Ive been to ryans page before, pretty awesome stats, but most things are done by brand name not cc ect so I wasnt a hundred percent hence the questions. I was seriously looking at the 383 option because I can get a new cast crank flat tops and performance rods for this setup at $500aust (about 300US). Why wont the heads be any good for this setup, surely more compression the better. I was hoping to run about 10-10.5 to 1 compression, like I noted before detonation wont be a problem because this car has never run on petrol in the last 15years. It runs on pure LPG, I have the cash sitting ready to go just trying to work out the best options. The carb doesnt really matter for my setup because it simply acts as a throttle body for the gas. I was also told maybe changing my diff ratios might obtain what im after as well, currently cruising at 2100rpm Im doing about 65-70mile an hour.
Thanks Steve