Need help picking power plant.

Sounds like a plan to kick those ricers ***!!! With 500hp I would say go with the 727. If you go big block (which really isn't that hard anymore to do) than thats the only trans you can use (the 904 won't bolt to a BB). I'd say a good engine combo would be a 400 based 451 stroker motor. Its a cheap and easy build using a stock 440 crank and rods with aftermarket pistons. Then top it of with aluminum heads & intake. Have fun, you found the right place to hang out and ask questions & learn. Now go beat on those ricers :blackeye::toothy7:
(also don't forget those chebbies & ferds :yawinkle:)