bought 87 t/a tpi auto few years back motor already rebuilt 355 but nothin else major ran 14.0 and started knockin last summer. just took it out this winter and have the oil pan off and found piston skirts swimming around. three pistons are visibly broken can only find pieces of two. either way ive been wanting more power so im gonna take advantage of this opportunity now. for one what causes a skirt to break off? do i need to go another size up in bore or will honing be enough and keep it .030" heads? i like the idea of porting stockers on lt1s but what abut TPIs? who does them? intake as well? not real familiar with 3rd gens yet have lots of studying to do just figured id see what input i can get.

 

Usually, when a skirt breaks it was b/c of improper piston clearancing. Usually too much clearance, or poor oiling, reusing old pistons...which you should never really do.
I'd check for deep scratches, and eccentricity, then bore it .030", and get some pistons with coated sideskirts.
TPI heads really not worth porting, I'd rather get some Vortec heads, and base intake to match...taller ports, way more air.

 

cheap power is with vortecs,intake,camshaft, build a 383 while it is out. love the torque and tpi are lower rpm monsters