The poly is a good engine. Tough as nails block, good oiling and cooling. The biggest thing is it weighs a buttload for its displacement, almost as much as a B series big block and depending on accessories, can near a stock RB.
The other issue is parts are expensive. Intakes are 3-5 times that of an LA or BB. Cam choices are pretty much custom grinds.
That said, with a stock cam and a stock 4 barrel and a good tune, they can hit 275-300 hp easily. Limited mostly by the crappy flowing manifolds.
There’s been people pick up 75 hp on a just a header swap on a dyno. Course header choices are limited and pricey. All depends on what you want to do.
