Hey guys like it says. I didnt build the motor so I dont know what the other person did. This is the numbers on the Piston head.

H345NP And the .030 for the bored over.

and 249-01-12-A

Doing LT1 Heads right now and would like to know what I,m paring them with.

 

Speed Pro hypereutectics.

 

OK. So are these ok or are they crap?? Never had to replace or do anything with Pistons.

Brand: Speed Pro
Product Line: Speed-Pro Hypereutectic Pistons
Bore (in): 4.030 in.
Bore (mm): 102.362mm
Piston Material: Hypereutectic aluminum
Piston Style: Flat
Compression Distance (in): 1.560 in.
Piston Head Volume (cc): +5.00cc
Valve Reliefs: Four
Wrist Pin Style: Press fit
Pin Diameter (in): 0.927 in.
Top Ring Thickness: 5/64 in.
Second Ring Thickness: 5/64 in.
Oil Ring Thickness: 3/16 in.
Quantity: Sold individually.

Piston, Hypereutectic, Flat Top, 4.030 in. Bore, 5/64 in., 5/64 in., 3/16 in. Ring Grooves, Chevy, 350, Each

 

They're fine for just about any kind of NA use.