New set of Clevite crankshaft main bearings.  These are the "P" series aka "performance".  These are full groove bearings. These are +10 undersize, for a crankshaft that is cut 10 thousands on the main journals.  Sold as a complete set of 5 (does 1 complete engine).  Fits the following:

70-79 Firebird Trans Am w/ 350/400 Pontiac Engine (326-400 is small journal engine)

NOTE : For all out racing engines or engines with forged crankshafts, we suggest the "H" series.  For street driven engines or engines with cast (stock) crankshafts, we suggest the "P" series.