Can a 1970-1973 400 2 bolt main block withstand the hp potential that fordged crank, rods and pistons will support, or should i stick with the stock crank, rods, and just put in fordged pistons? If someone could please lead me in the direction of a nice set of pistons, or any kind of engine sets. I am building from the ground up, and need all parts, so some sort of set i could buy where the parts are performance matched to each other would be great. Any advice will help.

Thanks for the help!

 

Also, What kind of horsepower can the stock crank, rods, and block itself withstand before i'll have to step up to fordged everything?

 

how fast do you want to go and how much HP do you want to make? answer these questions first. don't forget no factory rear end or trans would last for very long behind a high HP motor, unless some of the lucky ones off this board.

 

The stock 2 bolt 400 block is plenty strong.

Correct maching (align hone) and good ARP bolts are all that is nessessary. If you want to get really silly you can install ARP main studs.

Stock gm 400 rods are fine if you wan to stay with the shorter 400 5.565" rod length. I recomend going to a 350 style 5.7" rod. Either way use good ARP rod bolts.
A GM ( or other stock style) 5.7" rod will require clearance grinding on the rod bolt heads to clear the camshaft in a 400. Many aftermarket rods are designed to clear the cam in the block but all need checking and verification. Especially with roller cams. Don't assume it will all fit.

A good hypereutectic cast piston is more than up to the task of 500 hp with proper piston ring clearances and even ok up to 200hp Nitrous. KB and Federal Mogul have both hypers and full forged to choose from.

use a D dish piston with 64cc heads and flat tops with 72-76cc head on a street pump gas 400.

The stock cast 400 crankshaft is plenty strong. You'll break a aftermarket rod before you break this crank.