Quote Originally Posted by straightaxle View Post
More flow from a flat top piston?

But anyway, if the pin bore is the same new 4.8-old 5.3 then you can have your old pistons pressed off and the new ones pressed on to your 5.3 rods. the press fit in the rod will keep the pin from hitting the cyl wall so you shouldn't need the spiral locks.

I don't know if you can put PM rods in a rod oven. maybe someone here will know.


flat tops give you more compression than deep dish pistons.
what give you more flow are the heads, not the pistons.