Cut off line for Cast and stock internals

74Dusted said
What's the general census on cast internals & some stock parts (crank for example) at "x" boost before the need to upgrade to better internals?

The creature in question is a '69 340 Short Block with 60 over Keith Black Hyperereutic pistons, Stock forged crank, stock rods. (rotating assembly hasn't been balanced yet) Never assembled, getting the engine in trade for doing work to a friend's car.

Figured the Block & Crank would be a good starting platform for a mild Supercharged 340 to stick in one of my A-bodies. Don't know about the pistons, compression ratio is probably too high on them to use for the build. But is there a certain point where cast pistons are ok to use, or is it one of those deals where I should just get Forged pistons anyway?

Figured I'd keep the boost somewhat low and reasonable, Street Car. No need to go hogwild on exotic parts or an extremely radical engine

I have an engine similar to what you suggest.
Mine is a 1998 Durango 360 Magnum with cast (hyperuetectic) OEM pistons, stock rods, a cast crank, 9:1 compression (measured with a burette) and a mild cam from Hughesengines. It has a Vortech centrifugal supercharger running at 10 pounds of boost and makes 445 rear wheel horsepower, according to a local dyno shop test.

To control potential detonation, I have a Snowperformance Boost Cooler water/methanol injector set to start spraying at 3 pounds of boost, and an MSD BoostMaster cockpit-controlled retard unit.

I have had no head gasket, or other boost-related problems with this engine so far.

The engine is in a '72 Valiant 4-door sedan.

Installing the blower reduced the car's e.t. from 13.35 to mid-11s, and the MPH increased from 102 to about 118, Made a whole new car out of it, but you have to be careful; detonation will kill a combination like this in a heartbeat... Be careful with mixture and spark advance, and you'll be fine.

Good luck!!!

Here is the Chassis-Dyno sheet and a picture of the car it's in...