So what is the deal, are they cast or forged? Did they come in say a 1/2 ton 318 or only in the really big trucks with 318s? I have heard they are shot peened, is that true? I may be getting a 71 out of a 71 truck real soon.

The old 318-3 truck cranks were the hot item in the 70s and 80s. They are real strong forged units. You can tell them apart from car cranks because the throws on the rod journals are solid ( no drill hole through the center)The only problem is that these cranks are very heavy. You will have to lighten it up a lot to use with modern rods and pistons which equals $$$ my

If you can get an old 318 Poly motor they had those cranks in them also. They wouldn't be any heavier than a stock 340 steel crank as far as weight is concerned.

They did not come in a poly 318. They are heavier than a 340 crank. Take a look at the picture. Notice where the rod bearings ride....its solid. It has to be a few pounds heavier.

So would it be in a 71 1/2 ton?

Look on the block identifier pad. If there's an "E" there it is a cast crank.

I highly doubt that any 71 half-ton had a forged crank. I've got one in my back yard and it has the "E" on the ID pad. Of course, it's a Mopar, never say never!

The real question is why you think you need a forged crank. 318/340 cranks are not prone to breakage at power numbers the block can handle. Forged cranks don't make more power. Dirt track sbc 350 drivers use cast cranks as a matter of course.

What's happening to the rest of the truck? Out here they are becoming more popular smoothed and dropped.

R.

Just an old 318 2wd long bed truck. I am trying to figure how much I can spend to buy the truck based on what I can use and sell. I am thinking about putting my 414 stroker 340 in it so I did not want to throw away a good steel crank that I could sell.

400+ cubic inches in that truck should give you traction problems. Sounds like fun. My '71 "donor truck" has a front anti-roll bar, but some nimrod cut it with an arc welder. Does your truck have a working bar? It's the first I have ever seen on a beam front axle.

R.

Weigh both and then tell me honestly which one is heavier.

my 65 poly truck engine had a forged crank

so did the 273 engine I rebuilt