Machine work for stroker?
 

If you are going from the stock 376 to a 416CI crankshaft do you have to have machine work done for it to fit? One shop said I'd have to grind it down, another didn't even mention it.

They will need the block (machine work done... line hone, bore hone... ready to assemble), new bearings, full rotating assembly... then they will be able to answer that question.

Many variables in crank, con rods, rod bolts... various brands. Nobody can tell you for sure until trial fitting.

I have a 416 in a road course stock car that was built using a new LS3 block and Manley stroker crank. On the bill from prepping the block is - line hone mains, deck plate bore hone, debur and detail block 1 hr, deck block to zero deck height at 9.230" . Nothing specific to clearancing the crank or rods, unless they included that in the 1 hr charge for debur and detail block.

I suspect you will have similar machine work needs... perfecting the line hone, deck plate honing the bores, cam bearings install, block debur and detail, hot tank.... then you will know the final bore size, what bearings to get and be able to buy/provide the entire rotating assembly knowing what the final bore size is after hone. Then they will do a trial assembly and see if any clearancing is needed. Very minor if it is, but anyone is guessing until they have the parts on hand and do a mock up.

Assuming you buy the rotating assembly as a kit, the only machine work needed for the block is the align honing of the main bearings.

Honing the cylinders would be required for any engine build using new pistons/rings. Decking the block, while highly recommended, is not necessarily essential.

The crank, rod, and piston combo are engineered to work within the stock block configuration, without the need for major machine work.