Ha ha ha......... you guys know I had to chime in on this one.
You want light weight, eh? My aluminum Buick 215 weighs in at about 320 lbs from flywheel to fan. A full 300+ lbs lighter than an iron SBC from flywheel to fan.
I have three of these babies and the most I paid for one is $250.
Granted, I'm only getting 200 hp/240 ft-lbs torque in this current form but when I stroke it and/or go with a larger bore block, I should be able to get 250 hp quite easily.
Let's see.... my car weighs somewhere around
2000 lbs(stripped) - 2300 lbs(fully loaded '72 GT).
Let's say 2300 lbs divided by 250 hp equals 9.2 lbs per HP.
Compared to a 3000 lb car with a 350 hp engine getting 8.5 lbs per HP.
Sure, I'm lacking power but I can turn and brake much more effectively. .... which makes for a whole different kind of fun.
OK...... I'm done here.