Just curious since I picked up this 73 350. It has been quoted as 74 is the change over to the light weight junk crankshafts, is this true?

 

I thought it was in 1977 to coincide with the windowed main web (lightened) blocks. Maybe I'm wrong?

 

BTR mentioned 1974 in his book but there is some wrong information. No, both my 76 350's had no "N" on them, looked the same as my 260, 307 and 403 from 77 and later motors.

 

So did the cranks look different, as less metal for reduced weight, or just lacking an "N" on the casting? I recall some discussions on ROP that some had an N and some didn't, but I don't remember the details of that.

 

They are reduced weight and without a doubt weaker. A few of us figured the failure point on Macar1993's 10 to 1 403 was the factory lightweight crank breaking in three pieces and tore up the block.

 

I meant did your two 1976 cranks look different than the early cranks with the N cast into them?
Or did they look like the 1977-up cranks from windowed blocks?

 

My 76 crank has.. maybe 2, atleast 1 ( cant verify now) holes through journals which hold connection rods.

 

They look the same as the 77 and later cranks, if I remember right. I will take a pic when I pull the pan off my 76 350 in the next few weeks. Anyone using these light weight cranks in builds, need their heads examined.