what pistons to run with set up??a bit of help

Why not forget the 302 heads and use a set of magnum heads? Much better option.

IMO, a lot depends on the level of the build. (Power sought after)
While on the surface, the Magnum head sounds good for a lot of high powered options, the question still begs, at what point is this head a favorable option to use over a iron head, in this case, a ported 302.

Also, it i a price of conversion with the Magnum heads if this applies to a "LA" engine at current time of build, as well as the over all cost vs a ported 302.
Even if it is a regular Edel. head being used.

Lets take price out of the problem. Lets just look at the head itself. And to further level the field, make them both aluminum or iron heads. Yes, a Iron version of the Edelbrock head. Imagine this.

What your left with is port size & shape, valve size.

Which one will fit the engine better?
Will the smaller port one port out well and be a benefit to the engine over the other head?