273 crank in 318 bennifts??

[toolmanmike]

The '68-71 318's were mostly cast cranks too. Some truck and other industrial engines still used forged ones, even after '72, but not all. I mainly found them in manual trans applications. All the '67 and earlier small blocks had forged cranks. In swapping around small block internally balanced cranks between engine years and sizes, always check the converter hole diameter, pilot bushing hole if it's a manual trans application, and rebalance the recipricatiing assy as the bob weights are all different. Use the balancer that matches the year of your pulleys.

Sorry, I mis-spoke. I was thinking about 340 cranks and not 318 cranks. tmm

 

[67 gt]

so i have came across a few threads were people say they put a 273 crank into a 318.....but never really specified why...shorter stroke ???gain rpm or do you gain torque is my real question...:colors:

If your looking for some Quick throttle response use some scat i beam rods with the arp 7/16 rod bolts,kbs 167s your choice of full floating pins or pressed,with those 2 items you will strip just over 2 kilos in rotating mass thats not including the crank when it gets balanced to offset piston,rod weight differences,with a good cam,duel plane manifold with some decent heads watch that 340s little brother wake up!

 

[toolmanmike]

The 273 and early 318 rods are already 100 grams lighter than the 340/360 rods. Mopar used a heavy pin to offset the lighter small bore piston of the 273 and the 273 rods were full floating pins right off the production line.

 

[Dana]

Just weighed 5 small block cranks
71' 318-cast
77' 318-cast
69' 318-cast
67' 318-forged
MP 3.58 stroke with 318/340 mains -cast
All ranged from 48lbs to 52.5 lbs the cast 69 crank being the lightest, the cast 77 crank the heaviest. None have ever been turned. The MP crank has some mild factory bullnosing/knife edging

 

[RustyRatRod]

Lots of mis info in this thread. I have had both the 273 forged crank and the 318 cast crank on the scales. The 273 forged crank is lighter. The one we had was about 3 pounds lighter. Also, the 273/early 318 rods are lighter by a long shot than the later 318/340/360 rods. Balanced my share of those too. Of course, all of this could require rebalancing, depending on which piston you use. Lastly, no need to worry about the lighter rod's strength. Mopar Performance offered a performance version of the 273 rods using the same forgings as factory, but with good rod bolts and balanced very closely. They are long discontinued, but they do pop up on Ebay from time to time and they sell for a high price, because people looking for them know what they are. I suspect you could make a 340 scream real good with the 273 crank, rods and some really light pistons. I wouldn't be skeered to run them at all.