Thread: When to upgrade big block internals

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What is your opinion on when to upgrade the crank and rods in a big block Chevrolet (1975 454). In other words how much power can a stock crank handle and the same for rods. Is anyone running a 700 hp engine with a stock rotating assembly with success. I do not want to have an expensive crank and rods just to say that I have them. Thanks

most everything stock won't surpass 500 HP, because it's cast parts, you need forged stuff for that amount of HP.

I've run 600+ hp and had no problems. Raced it and drove it on long trips pulling a camper. Although I think it's good insurance to have a solid bottom end, it's doable with stock parts.

Originally posted by pro70z28
I've run 600+ hp and had no problems. Raced it and drove it on long trips pulling a camper. Although I think it's good insurance to have a solid bottom end, it's doable with stock parts.

i have done it many times to. big block can take alot if built right .

you cant really use HP as a yard stick for determing if a part will survive. there are alot of variables & differant ways to make HP.
RPM is critical, generally under 5500 RPMS your safe with stock internals. add a good set of rod bolts & you can go a little more.
A set of light weight pistons will take some strain off the stock crank & make it survive longer yet.
a machinist I know & trust prefers cast cranks over steel in applications below 6500 RPMs because cast cranks are generally lighter than steel (unless you buy a nice piece). He suggests a good set of light pistons & good rod bolts in the stock rods, & good machine work.