Edelbrock / RHS heads, or go BIG block and put it to bed!

17,000 miles isn't much, not like its got a 4 inch stroke.

The 9.5 compression isn't high enough for aluminum heads, you might lose power over good flowing iron heads.

The breakaway converter is junk compare to the streetfighters. I got a TCI 10 inch and light throttle it feels tighter than my old breakaway. I would swap converters. It help, not sure about 6 tenths but a few it do.

You could also just mill the heads .030 and do a valve job and fresh springs, run a thin head gasket and with a 10 inch converter you just might be close to 13 seconds flat.

The 440 would be better but way more costly, I would save my penny's for fuel cause its not getting any cheaper. plus you would need a 727 trans and yeah the weight will increase in front and traction in back will go down..can your car lose some weight