Early crank toughness...

Looking for some input from guys who have experienced crank failure with the OEM cast crank used in the pre-Eagle engines. I have spoken with two shops who have worked on these engines (stock rebuilds) and they don't have any experience with the widely held opinion that they are prone to breakage.

I putting a plan together for a second engine for my dirt car and will use an early 5.7 block using the OEM crank turned down to for 1.888 journals to utilize the NASCAR Pankl rods I have in stock. I may use the early heads or Eagle heads... not sure. Light weight pistons. Trying to hit the 650-700 HP mark using a single 4 barrel carb and the MSD 6 ignition.

If I can get some reasonable dyno numbers I'll build something a little tougher on the next build.

Mopar was always known to have some good quality cranks/rods in the past but I'm not sure the mexican made parts are up to the task.

That's more than most builders will run a 5.7 crank that is not turned down to 1.88, I would never attempt that with the 5.7 crank, the casting is good but not that good. Maybe a 6.1 crank would be worth trying that on, at least they are forged.

stock rod journal crank will take it the rods won't,,a 1.88 might be pushing it with the stock cast crank.....do you plan to on center the 1.88 journal ? or are you trying to gain some stroke? the pre Eagle heads need a lot of work to get you to 600Hp @ 345-360Ci, 700Hp @ 345 Ci is 2.02 Hp/Ci you will need some serious RPMs to get that. best flow #s I've found on the interwebs for the Pre Eagles is 340CFM @ 650 and I still think that was optimistic.

There was a guy on here a couple of years back that did a roundy round Gen III using a 6.1 crank and he ran into oiling problems due to it being cross drilled and starving the rods at high (7500+) rpm? He got it solved and made a ton of power, I think he went with an aftermarket crank.