440 Steel crankshaft question...

[64SF]

The only casting numbers/marks I can find on this steel crank is shown in the below pictures. Any idea what this crank is out of? I read somewhere that a steel crank from a 6 pack engine has to externally balanced.

In second picture the characters appear to be F70. I don't see any other numbers on the crank. Thanks

 

[1wild&crazyguy]

Because the connecting rods in 6 pack motors were so titanic in size and weight...they had to add external weight cause there wasn't enough counter weight on the crankshaft to do the job of balancing it.
steel crank is a steel crank, thats another steel crank.

 

[Moparmatt72]

You can turn any external balanced crank to a internal just need a different balancer, will just need to take the rods, pistons, crank and flex plate if auto or flywheel if manuel to a good machine shop for a good balance job.

 

[1wild&crazyguy]

You can turn any external balanced crank to a internal just need a different balancer, will just need to take the rods, pistons, crank and flex plate if auto or flywheel if manuel to a good machine shop for a good balance job.

If you lose the 6 pack rods, no loss there, and used the regular dampener for a internal steel crank motor i think you be on or real close already.

 

[Seventy]

I prefer non 6 pack rotating assemblies with 6 pack pistons, the older lighter rods and a steel crank, rebalanced by a decent machine shop... BUT, now the issue is cost, you can get a complete balanced rotating assembly for a couple thousand bucks, so now if you do the math.
$600 for pistons
100 for rings
150 for bearings
350 for balance job
90 for bolts
80 to remove and replace pistons
150 to turn crank
that all adds up to over $1500, so for another $600+ you get a complete stroker rotating assembly and can sell your rods and crank.... If you ask me thats a no brainer, same thing with the aluminum heads, $1000-1500 for a set of alloys when you are going to spend $400 in labor for valve job and assembly $150 for cleaning and checking, $300 for valves, seals, retainers, springs etc - for a couple more hundred get aluminum heads and call it a day... sell your 906, 516, what ever for $200 and save yourself some weight and time...

hope this helps, I am a hypocrite because I always end up having a set of 906's done, vs buying aluminum, lol, BUT I am doing restorations to keep them as original as possible, sooooo I like having an original engine... BUT if that isnt important to you, you paint them alloys orange and no one ever notices, lol..

 

[HT413]

I prefer non 6 pack rotating assemblies with 6 pack pistons, the older lighter rods and a steel crank, rebalanced by a decent machine shop... BUT, now the issue is cost, you can get a complete balanced rotating assembly for a couple thousand bucks, so now if you do the math.
$600 for pistons
100 for rings
150 for bearings
350 for balance job
90 for bolts
80 to remove and replace pistons
150 to turn crank
that all adds up to over $1500, so for another $600+ you get a complete stroker rotating assembly and can sell your rods and crank.... If you ask me thats a no brainer, same thing with the aluminum heads, $1000-1500 for a set of alloys when you are going to spend $400 in labor for valve job and assembly $150 for cleaning and checking, $300 for valves, seals, retainers, springs etc - for a couple more hundred get aluminum heads and call it a day... sell your 906, 516, what ever for $200 and save yourself some weight and time...

hope this helps, I am a hypocrite because I always end up having a set of 906's done, vs buying aluminum, lol, BUT I am doing restorations to keep them as original as possible, sooooo I like having an original engine... BUT if that isnt important to you, you paint them alloys orange and no one ever notices, lol..

This, I believe, is what has driven the pricing of 440 source stuff. It seems the only way going OEM can beat the price is if you happened to find a killer deal where the 'other guy' is losing money.

Think of it from a Brand X point if view. It almost NEVER makes sense to go OEM on a small block Chevy, because nice aluminum heads can be had often for less than the price of springs and a valve job.