What can a 400 Be stroked out to?

 

I know you can get a 4" stroke crank that would bring it to a 427 on an original bore (440 when .040 over) but I dont know if it will fit between the pan rails on a stock block.

 

a .30 over 400 is a 433.... but the only logical reason to stroke it that much is when making a motor so powerful that i wouldnt be using a GM block to begin with.

if i was using a 4" crank, i would use a motown, dart, or other aftermarket block.

 

With the right machine work it can fit. But, the bigger point to make is the size of the pistons compression height. With a 4" stroke, that leaves a 2" radius. Using a " rod, that's up to 8". With a standard 9.0xx" deck, that leaves a 1" compression height. Not too many pistons out there with that height.

Like the dude said, I would use a tall(er) deck aftermarket block.

 

My friend has a 421ci in his S10. It's a .030 400 block with a 3.875 crank. Solid roller, Dart 210 heads, big stall, ran 10.56 at 123mph

 

A 421 (3.875") is about as far as you would want to take a stock 400. A 4" crank will fit, but requires some grinding to the pan rails and lower cylinders. A 3.875 will require some grinding, but nothing major. a 4" will put the structural strenght of the block at a questionable point. If you were building an all out race motor, thats one thing, but for any type of dependability, stay on the smaller side.

If you are going to go to a 427/434 (4"), you would be best off with an aftermarket block.

 

it can be stroked out to 350 cubes or less too if you want to go in the other direction LOL