Just opened my 540 bulldogs and it looks like they have to be punched out to 4.500 bore. I thought I would have no problems finding the pistons but I am. The stroke is 4.375 I do not know how long the rods are but they are stock 540 bulldog motors. They need to be 557 ci now and I need pistons. Does anyone have two sets of these sitting around new or used. Also if you know who sells these pistons off the shelf. I called a GM performance dealer to see about the piston for the 620HP ZZ572 since it is the same block and stroke as my motors. I hoping that I do not have to have them made. Help Help Help

I believe your rod length is 6.535 . call JE pistons in CA they will make them for you and the turn around this time of year should only be a couple weeks . You will also need the weight of the piston , so they can match the weight or you will be rebalancing the rotating assembly. You could also try calling Sterling because they build alot of 557 motors and I'm sure they keep the pistons on the shelf. Also try Randy at Cobra he might have some . Tom

Thanks

Ross Pistons

JE... for sure... good stuff and quick turnaround this time of year. If you are going to use the same crank and rods...just send them one of your old pistons and tell them what size bore you are going to run and let them do the rest. The will figure out the compression height and ring land placement.

ordered mine from je ,have the part# if you need it started with bulldogs also.

I've got 2 sets of Ross flat tops that are 4.500. To be used with a 6.535 rod length and came out of my 557's. (4.375) crank. You got the cranks? PM me if you're interested.
I think I may even have a few spares.

Frank

You can try Mel Riggs / Riggs Marine, He's done quite a few of those. 920 872 2728. I'm pretty sure wiesco makes a set that would work for you.