Well my 406 is starting to come together, I picked up the block/crank/rods today from the machine shop. Now I am going to put it together and check to see how much clearencing(sp?)I am going to have to so with the 5.7 rods. The cam I have i s a xtreme roller 288/294 adv 236/242@.050 can't remember the lift off hand. I expect to spend this thing to about 5600-5800, it has a stock crank, reconditioned rocs w/ arp bolts and KB silvo lite pistons. I have read alot about balancing and some say its good others say its a waste of money. I talked to my friend at the machine shop who spins his 289 race engines to 9500, and he said with the KB pistons, it probably wouldnt hurt to have it balanced, he said it might help with bearing life, and if there was a vibration in it, it would help that too if I had it. So he said its my call, I said well hell your no help. And I am not even going to ask the guy that does the balancing because I am sure his answer hell yes you need it balanced, along with your lawn mower engine. Any insight? Thanks
Jason

 

Is it needed?No..is it something I would recommend?Yes.I have every assembly I am going to build balanced every time.Whenever you change pistons,rod bolts,rods,etc around it is always good practice to have it balanced.Hell I even get my clutch and flywheel assemblies balanced..and it makes a huge difference in how they perform.

 

If you have to ask if you need Balancing on a new motor, the answer would be NO. But by your question it would be in your best intrest to have it done. So pay the the extra cost and have it
done. One less problem to worry about.