My 425 engine is dismantled and not matched to the connecting rods & caps. I thought it would be better to just buy new ones, however, the engine builder that I spoke with recommended using the old ones, even if one of them is not usable.

What do you guys think? One of the pistons had to be hammered out of the block and I would not trust that connecting rod.

 

Hammering the pistons out really should not hurt the rods. Your question is almost impossible to answer without having the rods to look at and measure. Thousands of engines are rebuilt using the original connecting rods and it is not an issue. Your machine shop should be able to examine them and tell you what to do.

 

Dont think you can buy stock 425 rods new. Have yours checked for cracks and have them reconditioned, no problem.

 

Molnar makes a nice aftermarket rod. You would have to call them and see if they have any in stock.
425 Oldsmobile Connecting Rods

 

They should, I just got 2 sets from them not long ago. I’m a dealer for them as well.

 

Well, I was also trying to determine the best course of action, considering my connecting rods are suspect.

Is it any more difficult for a machine shop to use new connecting rods vs old ones? Wouldn't new ones be better? Are the connecting rods balanced a certain way or do the journals need machining?

 

Unless you're doing a performance build that would be more reliable with newer, better high performance rods have the machinist check out the stock rods. 425's were strong reliable motors, if the stock rods check out or even if they need some work they should be better than good for a stock build. Compare the costs and then make your decision.