Depends on the efficiency of your turbo/supercharger. I had an APS kit with 402ci, basically spooled from idle and ran out like a diesel, didn't like rpm, but made lot of torque.
Put a 390 piston next to a 408 piston, the difference is very clear, 390 has thick ring lands that support the rings better than a 408 piston. Also keep in mind the piston acts as a heat sink, thick 390 piston, heavier but can absorb more heat.

When I came up with the idea for the 390, Callies just came out with this C-Series 3.825 crank, the first ones I had seen measured very accurate, its a forged crankshaft with a keyway, offered a good option for anyone with a D1SC or 88mm turbo.

I'm surprised no other LS builders came to market with a 390 based motor.

 

how does the 390 piston compare to the 370 piston

 

Off the shelf 370 piston is ok, but what they do is put the oil ring above the pin so it doesn't need a spacer. I believe they have a standard .270" ring land. Generally they come with standard steel .150 wall pins.

You could make a custom 370 piston for plenty of power, the shelf piston covers up to around 1200hp, thats good enough for most.

 

1050whp threw my th400 is all im after

 

Thats actually alot to ask for; At that level I would recommend 1/2" head studs.

Spooling a 98mm turbo, I would recommend more cubic inch than a 370... 390, it doesn't have to be AES, anybody could build a 390 engine.

 

****, i was told my AES390would handle 1000rwhp all day long. callies crank/rods diamond pistons.. arp hardware, head/main studs...twin tc66mm turbos

 

Its a 98mm turbine and a 88mm compresssor gt5018

 

3.265" crank, LSA Heads, Soild roller, 8000-8500 RPM, 11:1, E85

Loosen the converter a little down low to take advantage of your new found RPM and don't worry about spooling the turbo

But out of the options your listed I would build the 370". Your going to be able to make more power with your turbo before running into drive pressure issues.

 

I all ready have a running car. But i hurt my stock crank. wastegate couldent flow enough and i saw over 30.5 Lbs boost not sure exactly how much boost it made but on hptuners it flatlined the map sensor. I have callies rods and wessico pistons. Tfs heads and a proflo intake and a custom spec cam. Really all im doing is looking to replace my crank. But if its more then just a crank and bearings then i may look in to a new shortblock.

 

Well turns out the wrist pin retaining clip fell out and the wrist pin scored the cylinder on number one.
not sure if the block can get bored out enough yet.
tons of options now on the table for me right now.
Not sure what to do. Any ideas guys