bcfountain

what bore are the pistons,30 over?how much $$?

Pat McPherson

Stock bore is ø4.470inch.
Don't go .060 over unless you have to.

jeff1000man

High end main bearings - $100
High end rod bearings - $100
cam bearings - $40
Refresh at machine shop $150
Set of high end rings - $100
Timing chain and gear set - $75

Total $565 for a brand new bottom end on your engine using the best parts available.

Peice of mind that you don't have to touch it for another 450 hours. - Priceless

By the way. THat is using the best of everything. You can probably put it back stock for less than half that and still be ok.

Vavle job and springs should only be another $300 a side - max.

Moral of the story, if it is out of the boat, you might as well tear it down.

kennyo

I assumed the 502 was a 4.5 bore. these are .030 over stock size. I have to make sure they don't hurt them pressing the pins out. Probably take between $150-175 for them.

Young Performance

I totally agree with the other responses, while it's out, do it all. I think Jeff's number are a little low for the refresh. Parts numbers are correct. The biggest problem I have seen is that the vast majority of the 502's won't go back standard bore with 400 hrs. They run very little piston to wall clearance. By the time you hone the cylinders and get them round again, you have opened the bore to much. GM recommends no more than .0045 clearance. If you run to much clearance, you will break a piston skirt because of their high silicone content. DO NOT put new rings in a cylinder that is not honed to perfectly round. They won't seal worth a damn. I would not put it back without doing the bottom end while it is out, that just seems like a waste. Hope this helps and good luck, Eddie.

Pismo10

Bore to 4.5, stroke it to 4.25 and make a nice 540. If you find you need a new crank for some reason, probably not, go 540.

jeff1000man

You can get a complete rotating assemblie for the bottom end using all high end stuff (good to 1000hp) for under $2000 delivered.

My prices earlier didn;t include labor, but I was just trying to make a point.

Good luck with your project.

kennyo

I was on that bubble last week until I figured in the $$$ for a bigger cam, pushrods, the lifters, etc.. Easily another $2000

bcfountain

how come you are using pressed in pins?why not floating.had bad luck w/spral-locks before?

Young Performance

Stock GM rods are a press fit. Has nothing to do with the piston. Also doesn't make sense to put bushings in stock rods for what you can buy a set of aftermarket h-beam rods with bushed ends and cap screws.
Eddie