Need a Good Website Calculator for ET to HP

For the quarter, I will have to see what it does this weekend. A 70 Duster 2900lbs, pretty much stock body, interior, about 3400 with the tools in the trunk, a pilot and co-pilot, a 360 block instead of the /6, the 727 instead of the 904, and the 8-3/4 instead of the 7" I think that came with the slant six which they calculated the 2900 with?? I could run by a cement plant some day and get an accurate weight if I'm lucky and the guy likes old cars. My 1/8th speed was 81.40mph. I will have to see what she does in the quarter. I am playing with mods, trying to see what helps the most. Tires are 275 50-15's, about 24-1/4", 3:23gears. It is a street car really.

RPM heads, 10:1 compression, Air Gap, 3-step headers, Holley 750 I have to get the cam specs if you need them, but its rather big, not full race though.

I appreciate if you could give me a ball park off the 1/8th. (81.40mph)