That's pretty light and it'll leap out of the hole with those gears, but you'll need all three gears for the 1/8th mile. If you ever run the quarter it'll probably run out of revs.
Is this a real car or just in planning stages at the moment? The reason I ask is there's no real reason to strip it down so much if all you want is mid-high sevens over the 1/8th mile. Although losing that big back glass will probably help and you can probably sell the glass for bucks (I hear they're hard to get) to buy other parts.
Personally I wouldn't be cutting the firewall or floor out of a car like this just to replace it with aluminum. What's you local strip rules? Do you need a cage for those times? Down under we don't need a cage until we run quicker than 7.0 on the 1/8th (10.99 for the 1/4).
Get it down to 2800lb (race weight inc driver) and put a nice 1hp/cube 360ci small block in it with 4.1gears and you'll be in the ballpark.
Edit: I came up with this in my head and then decided to double check using my Mopar Chassis book as recommended by "75 Duster 360" above and it concurs.
2800lbs + 360hp = 117-118mph in the quarter (mid 11s)
3000lbs + 360hp = 114mph (high 11s)
3400lbs + 360hp = 109mph (mid 12s)
All time depend on optimum selection of right gears and converter.
A good rule of thumb for converting 1/4 times to 1/8th times is by multiplying ot dividing by 1.555.
If you car runs 11.99 on the quarter divide by 1.555 and it gives you 7.71 on the 1/8th.
It's not precise but close enough for horse shoes and hand grenades :)
