63-360hp crank and rods
Building a 63-360hp motor and need to know best crankshaft and GM rods to use. Does anyone have GM part numbers and can the rods still be bought from GM?
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Re: 63-360hp crank and rods
Are you saying you don't have a crankshaft?
The pre-'66 OE rods are boat anchors - junk... prone to fail. Get a set of Eagle SIR5700 rods - about $250 a set.
Duke -
Re: 63-360hp crank and rods
No I do not have a crankshaft.Comment
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Re: 63-360hp crank and rods
OE 327 crankshafts are getting hard to come by. Most used have been turned, which removes the Tufftride surface hardening on SHP/FI cranks, which had two different forging numbers over the years. I recall one starts with a 2 and the later version with a 4.
I believe the 250/300 HP cranks have a different forging number due to a smaller counterweight configuration for the cast pistons, which are lighter than the forged SHP/FI pistons.
You can buy a new Crower crank. They are very high quality, but expensive.
Others may be able to point you to other sources.
DukeComment
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Re: 63-360hp crank and rods
Jerry------
The best small journal rods available from GM were GM #3864881. These were discontinued in September, 1987 and replaced by GM #12333077. The latter was a remanufactured 3864881. It wasn't available for too long and was discontinued without supercession in July, 1988. You can usually find the 3864881 rods on eBay. However, aftermarket rods are the best.
The best GM crankshaft was GM PART # 3838495. This crankshaft is identified by forging number "2680". This crankshaft was discontinued in November, 1987 and is probably pretty hard to come by in NOS form.In Appreciation of John HinckleyComment
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Re: 63-360hp crank and rods
IIRC, "4577" is the other crankshaft casting number that comes to mind. I think this is the other larger counterweight configuration similar to the "2680".Comment
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