Huh? Where did you get that from? L34 is far from stock 308, but A9X engines were normal production L31 engines bar the fan, 1 x exhaust manifold and I have heard that the L31 Torana ran a slightly different cam (so did the manual 202 ADR27A Torana by the way). They only have HT engine number prefix to signify that they are from a Torana (H) and a 308 (T). HP 308 engines are just normal early 308 engines from HT, mainly Brougham.