Big Block Rod Lengths

[68/70Vette]

For my big block build-up, I'm trying to buy the bits and pieces as time goes by to avoid financial shock of final engine build.

I was thinking of choosing a rod set today, and noticed that , say Crower, has about half a dozen or more rod length dimensions for a 454 (i.e. 4 inch stroke Big Block, of course with more piston diameter you can get to 502 with the same rod.)

What do I need to think about for rod length? I'd thought that just buying a length that was the same as factory would be ok. Maybe some of the light weight pistons need different rod lengths? I'm planning on 10.5:1 compression ratio. I'd like to internally balance the 502, so maybe light weight pistons need non-standard rod lengths?
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I've already bought the block (Keith Black aluminum), Brodix aluminum heads, Black billet 454 (4 inch stroke) crank, ministarter, Morosco oil pan, many parts for a Serpentine assembly ($$$$) for the nose, Richmond 5 speed, new OEM frame, new front suspension, SSBC Calipers, ...etc.

Thanks

 

[TimAT]

The standard 454 rod is 6.135 long. Most guys from what I've seen use a 6.385 rod on a 4.25 stroke BB crank. I think (not sure if I'm correct) that it's something about the angles a rod goes thru during a cycle (1 time top to bottom to top).

 

[68/70Vette]

The standard 454 rod is 6.135 long. Most guys from what I've seen use a 6.385 rod on a 4.25 stroke BB crank. I think (not sure if I'm correct) that it's something about the angles a rod goes thru during a cycle (1 time top to bottom to top).

Thanks but I think my crank is 4.00 inches. So it looks like 6.135 is the stock length.

Sorry about that squirrel problem!!!!

 

[TimAT]

Stock 454 stroke is 4.00. I was think you were asking about combinations for a longer stroke crank.

 

[pcf_mark]

I believe the longest rod you can get in the block is always a good idea for torque development. 6.135 stock for 396/427/454 but +.250 longer is common upgrade. Your cam manufacturer may taylor the cam specs slightly if you go with the longer rods. With Brodix heads you are on your way to big power - you need the strogest rod regardless of length!