I'm almost finished with my build and am going to be installing after degreeing the cams in.
MMR stage 2 heads
comp 270ah cams, comp springs
reichard racing intake manifold
75 mm accufab TB
60 lbs injectors
MSD COPs
Turbo headers
Hellion single kit, hot and cold side
76 mm CX racing turbo (going precision 76 in a few months)

I have a full balanced bottomed with manly rods, 9.8:1 .020 over mahle pistons
all arp ( heads and bottom end) but crank is cast.

My last motor had a cast crank with a 2.1 Kenne Bell and nos and I had it around 700 wheel several times and 550-600 a lot with no problems. After running the KB car for 2 years I took the motor out and took the crank in and the machine shop polished it and said it was good to go, I didn't use it for my new build, I got a new one. I'm looking to make 600-650 and daily drive it on pump gas. Am I over confident with that cast crank? I am over budget blah blah blah, you guys no the story so having to find, purchase, and take it back to machine shop to have a new crank installed would not be ideal but also don't want it coming apart on me. I plan 6500 RPM.

 

Cast steel modular cranks are very strong, 3v 4.6 crank being the best I have seen to date. The real limiting factor is rpm. The cast steel crank is around 20% lighter and lacks the additional center counter balances the forged steel units have. Keep it under 7k rpms and she will do just fine. Additionally that kb puts a lot more stress on the crank pulley than a turbo setup does so if you ran 700rwhp with it I would have no problems running it with that turbo setup. I'm running my stock cast steel crank still I spin to 6800rpms and make 766rwhp with it, been beating on it since 2010. I would recommend a quality damper, I run an ATI.

 

I'm going to run it. If it breaks I'll let you know but I just don't see how it could with such a short stroke. Thanks for the feedback and I'll make sure to keep it under 6500-6600.