@Joey N When you said you have flat top pistons, the stock engines came with flat top pistons a lot and performance pistons are also flat top often but the difference is the performance pistons are often taller for more compression. They also have valve reliefs.
What are you thinking power wise? How much? Is there a goal for the time slip? Or is this just a general statement of a nice powerful street car?
With the big block in the Duster & a reasonable gear ratio (did you have a gear ratio in mind?) you’ll be able to roast the tires easy. I had a 400 in a ‘71 Duster w/a 727.
With that OD trans in there, you’ll use the first 3 gears which end in a 1:1 so, that’s what you’ll race with or enjoy the most on acceleration. The OD drops the overall ratio. The math is the OD ratio multiples by the gear ratio.
OH! The speedometer gear will be calculated at the 1:1 gear to be accurate. Not the OD gear.
That set up will be a lot of fun.
