These two places will tell you how to get it done, you'll have to probably add some room on that budget though.

http://latemodelengines.com/
+1-713-849-4505 talk to Bryan.

http://hkracingengines.com/
+1-832-215-1840 talk to Erik.

HKE is probably cheaper, but takes a lot longer.

While I can always appreciate the idea of saving weight, you have to really look at where it is. Engine block, dry sump and all these things do add weight, but in a weight restricted class, if it is inside the axles, and lower than the top of the tire, that's really not a terrible place to have it. If you have ballast in the car, running a heavy exhaust and block/trans may not be as bad as you think it is because it allows you to keep the weight low and you can take more weight from things up top. If you've got ballast on the car that means you can move some weight around, just something to think about that I don't see people think about sometimes.

 

How did i forget these guys 2 of the best ... both are in the H forgot about Bryan & Eric both are really busy ... but money talks.

 

I am building a very similar short block combo that would fit your rules. I am using an LSA aluminum block with its stock piston oil squirters and nodular iron main caps that I am studding. It is supposed to be 20% stronger than the earlier blocks. It is bored to 4.080. That gives me enough bore to run a decent sized valve. I have a Callies Magnum Micro Polished 3.50 stroke crank with standard LS mains and Honda 1.889 rod journals that while not as light as an XL crankshaft, is still about 8 lbs lighter than the forged LSA crankshaft and it has nice contouring on the counterweights. The micro polish reduces windage, reduce oil temps and according to Callies test add a few hp. Mine is going to see boost so I didn't want to use the lighter XL crank. I have one with a 3.185 stroke and Honda journals at 36 lbs that would be nice for a N/A build but you can't get enough bore to get to 6 liters with it. I have 556 gram 6.25" Dyers top rods made from the 300m alloy along with coated bearings. I will be running Ractech pistons with a 1.25 compression height and DLC coated tool steel pins. This comb comes in at 366.07 CI or 5999.96 cc.

I hope you can figure out an LS setup within your budget. The 6.0 K&N cup Spec motors pushed 650 hp with small valve LS2 heads that only flowed 290 cfm on the intake, I just flowed mine off of one of those engines plus their rotating assembly's were all heavier too. With better flowing heads you could probably get close to your goals.

Since I didn't have any deadlines I have way less than half the retail in all new parts by scouring parts classifieds, Ebay and Racing Junk frequently. The block was the only used part and that was half the cost of a new one. Good luck.