Vehicle weight is around 3200 pounds. Camshaft will be chosen after compression ratio is decided upon. I will use a solid lifter cam. 355 rear gears.
I posted this same question 10 years ago when I first built the motor and was trying to decide between flat top and dished pistons. I ended up taking the safe route- went with dished pistons and 9.8 to 1 compression rate and was very happy with the results. However, I have not built many motors and I always wondered if I left a lot on the table by going with the lower compression ratio.
And by the way, I agree with IQ52 that an aluminum head motor does not NEED a higher compression ratio. Hot Rod did an article where they swapped absolutely identical heads on the motor, except one set of heads was iron and the other was aluminum. Dyno test showed minimal difference.