429 boss

what is the largest stroke crank in a 429 boss block

4.500 goes in with no issues, just make sure you get the boss snout if it's an origional boss motor and you want to keep the original accessories

i thought a 4.750

It will fit but the Pistons get pulled out the bottom pretty far, I wouldn't use one for any street application that you want to last, 4.500 is where I'd draw the line

I know old post

4.750 with a good size dome will call for a 6.600 rod, Which as stated above will pull piston down too far and wear out the skirts quick, about 40 runs on a set of pistons avg. Now its another story if you have a litle DOME. Then if you can use a 6.700 rod in a 10.300 deck block. But you could go with a 4.600 stroke and that will work fine.