Scat rods are better than Eagle rods, especially the SIR.

DO NOT use the 340 Edelbrock head! Use the closed chamber Edelbrock head. The only thing the 340 head will get you is lack of squish. Build the engine for pistons at deck level (zero deck).

TRW pistons aren't sold any more. They are now called Speed-Pro. They are heavy, 720 grams without the pin. This is a bigblock piston weight.

This is exactly the wrong piston to use in an engine built for acceleration.

You should be able to find a lightweight custom forging that weighs around 200 grams less and doesn't cost a bunch more. If you are not building a stroker then the 340 needs to rev to make power. Lightening up the pistons allows quicker engine acceleration and puts less stress on the reciprocating parts, bearings and crankshaft.

Sounds to me that your engine guy is stuck in a time warp (without Susan Sarandon prancing around).

R.