Will heavy TRW pistons work with cast crank 340

[cudaracer]

The assembled 340 short block I got is a 73 block, forged TRW L2316 +.030 pistons that have the number 266-99 stamped inside under the top.
The rods are #3418645. 

I understand this year crank was cast and externally balanced.

The questions I have are,

1.  Is that piston a bad choice for this setup using cast crank & external balance?  I understand there are newer and lighter, etc. but these are free and ready to go.

2.  My harmonic balancer is cracked at the keyway, so any advice there?  I found a $98 balance that can work with external (uses bolt on counterweight).  Is there a better choice?

3.  Are those rods adequate for a 400 hp build?

4.  I assume that crank can handle very occasional runs to 6K without issue.  Right?

5.  I also have to determine a torque converter with this setup, backing to a 904 auto and 3.23 gears.  Any advice there?

Thanks

[Strawdawg]

be nice if there were lightweight pins available for them.  I think as long as you try to keep the rpm to 6000 max, they should be fine...

[72cudamaan]

Buy a good balancer, and have new ARP bolts put in the rods. Then have them reconditioned. It will O.K.  Need
to know cam specs before choosing torque convertor.

[cudaracer]

Buy a good balancer, and have new ARP bolts put in the rods. Then have them reconditioned. It will O.K.  Need
to know cam specs before choosing torque convertor.

268/280 dur

.477/.488 lift

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=627&sb=2

This is for an e body cuda btw

[cudabob496]

Question is, what will the power gain be, and how much will engine longevity increase, ability to rev quicker, etc, if you use lightweight pistons.
Slogging heavy pistons in there has to hurt in someway?

[Chryco Psycho]

I would install new rod bolts , polish the beams & remove as much of the excess weight from the rods as possible, there are heavy pads on the top & bottom of the rods but you do have to be careful so that the lightest rod can be matched to the rest & is not too light  , make sure to have the whole assy balanced , you can remove some weight from the pistons also , the lighter you cam make everything the easier it will be to balance the assy . Once you do that I would have Mallory metal added to the crank to internally balance it then you can use a neutral balanced damper & converter