What a turd that was. They took the already weak Pontiac block and lightened it, reducing the durability even more.
The Turbo 301 was even worse. 210 HP from a turbo V8 is pathetic but they were up against the wall trying to make power without blowing it up and incurring a red wave of warranty service costs.
There may have been some 305 chevy engines in the 1980 and 81 Firebirds but I'm not sure.
