What is needed to turn a 1970 472 to a 500?

[fleetwood472]

Do I only need to switch the crank or do I need to switch the rods to? IF I do that will it have the same amount of power as a 1970 500 or are the pistons different to? Thanks - Justin

[pageboy]

Only the crank and pistons are different. The rods are the same.

[KJC]

Yep. ( I agree with pageboy)
If you buy new pistons, the Keith Black hypereutectics are only a little more expensive than cast stock replacements, if those are even still available for that year.

[fleetwood472]

Will the motor have higher horsepower and torque if I swap the crankshaft? Does anyone know how much it will have just by swapping out the crankshaft. Only reason i'm wondering is because I have a 76 500 and a 1970 472 but the crankshaft on the 472 is messed up. I am going to be running port injection which motor do you think would be beset for the swap? High compression 472 switched with a 500 crank shaft or a low compression 500? The motor will be going into a 78 fleetwood with the cadillac multiport fuel injection and 730 ecm from a 91 camaro with a custom burned chip. What do you guys think would be best? I'm looking for power but how much more power will I get with the 472 vs the lower compression 500 also how much of a difference in gas mileage will I see between the high compression 472 with 500 crank and the low compression 500? Thanks - Justin

[Al from MTS]

You can't just switch the cranks. The longer stroke of the 500 crank would pop your 472 pistons right out of the block.
The piston pin is in a different location on the 472 vs 500. That's how they could use the same size rods with the longer 500 stroke.
I take it this is a budget build up. If your 472 is wounded, run the 500.