Which Crank to use?

[Andy(UK)]

The story is that Ive effectively got two crankshafts to choose from. I purchased a new one when I was originally only buying an engine block, but then I found a long block so I now have two.

One is a brand new C.A.T products: CK-302 EFI, HO, Main 2.2486", Rod 2.1232", Stroke 3.000", Weight 43lb., 68-95 stock replacement crank, rated to 500 bhp which this is said about on CATs website
CAT nodular iron crankshafts are manufactured with modern vacuum casting process. The 80-60-06 nodular iron is the best material for crankshaft that exceeds OEM specification. The nodular iron microstructure consists of pearlite iron 80-90%, and graphite over grade 2 and grade 3 in iron. Every casting batch is analyzed with pearlite and graphite. The state-of-the-art CNC machine centers provide superior tolerance.
CAT nodular iron crankshafts incorporate these features:
- CNC machined to provide superior tolerance.
- All journals are micro polished to 5 RMS.
- OEM original journal radii for using of standard bearings.
- Larger chamfer at oil holes for better lubricating.
- Every crankshaft has been magnafluxed and ultrasonic tested.
- Every crankshaft has been fully dynamically balanced to original specification for immediate use.
- Every crankshaft has been surface oxidized blackened for rust resistance and hardness.

The other is the original crank which is still in my engine, current condition unkown as Ive not pulled the pan and caps yet. The bores are at standard and in excellent condition so I expect the crank to be similarly as good.

So which would I be better off using, the new crank or the seasoned one in my engine (assuming its good). Engine will have rpm heads, XE268H cam and run around 9.5:1 CR aimming for 350ish BHP.

Whats your opinion?

Cheers
Andy

[Jack21]

Here's what I'd do.

Remove the entire rotating assembly from your engine and sell it. It's a completely balanced rotating assembly that needs only cleaning to install.

Use the new crank, Eagle forged rods, Probe or SRS pistons, billet flywheel, and SFI damper. You'll need this all balanced anyway. Use a hydraulic roller cam for torque, or a flat tappet solid lifter cam for RPM. Top off with a decent pair of aftermarket heads, and you'll have a rock solid motor for your Cobra.

[Andy(UK)]

So as long as the journals are good Ill use the new crank, Ive got new Edelbrock rpm heads with the 2.02" intakes and rpm intake, I was going for the comp cams XE268H cam (mines a non roller block and I cant stretch to the roller conversion). I have Eagle SIR5090FP rods (not forged but stronger than stock) and was going to use Keith Black Hyper pistons. This should give me a nice motor, nothing mad but much better than stock. I may well try to sell the current rotating assy, someone might want it!

Cheers

Andy