I just tore down my 1971 YS 400 and i dont know if the crank can be turned. It has light gouging on it. It measures 2.99-2.98 at the main journals (measured with a cheap digital mic) and 2.24 on the rod journals. I have looked for a replacement crank just in case and I cant find one for a 3.75 factory stroke. All i can find is stroker cranks and rotating assemblies. The reason I want to stay with 3.75 is because i will be using a set of big valve high comp #16 heads. Maybe the crank can be turned. Is there anything wrong with a rebuilt/re-manufactured crank?
If you google "Ohio Crank" they list a crank for the Pontiac 400. It says it has the 3.75 stroke. It says its forged and about $680.Good Luck
Just get a crankshaft kit .The one I got was cut 10/10 and came with clevite bearings . $205 dollars . Autozone has them .
hello;if the gouges are too deep they can simply weld it and regrind it. they've been doing this for a zillion years.
Main brgs are available down to at least .030 undersize. Rod brgs are available to .040 undersize. King even shows a .050 & a .060 undersize rod brg on the Summit site. If you'd like to keep your crank, take it to a good crank grinder and let him inspect and measure it, to make a determination as to whether it's turnable or not, with the brg sizes available.