Wanting to rebuild and looking at new pistons. Which to buy?

[Will]

Anyone know what the compression distance is on an 83 258?  Was looking at federal moguls and wasn't sure if it would be a match. 

link below

http://ecatalog.federalmogul.com/Application.aspx?yr=1983

should this not work if you guys and gals have any recommendations please hit me up.  i would like to avoid boring if possible.

[eaglefreek]

According to that link there is only one compression ratio piston for that year . 470-AP is the part number. You may need to talk to a machinist to see if your block needs boring. If the block doesn't need boring, than your pistons should be fine and a new rings and a hone would be what you would need. I believe it is 8.2:1 compression.

[Demigawd]

these are the pistons i ended up going with
http://www.bulltear.com/catalog/product_info.php?products_id=242&osCsid=4534c2622ab952d8ce4d3cb690fa88fe

[wagoneerhauler]

EF has got it.  If your not going to re-bore the block then there's no reason to buy new pistons (in most cases).  However, if you rebuilding then why not have it bored.  I know more $$ but don't skimp out here; you won't be as happy in the end.  If you are ok buying the new pistons go 20 or 30 thousandths over.  Do it once and listen to the machinist's suggestions.

[Sunny]

I'd bore it out, for sure.
How high of compression do you want to go?

[BenM]

The pistons stay down in the bore a little more then normal in the 258, but they're also dished to lower compression. If you're going to swap the 4.0 head, and you should, then compression will go up because the later head has smaller chambers.

Make sure you check the numbers and get the right dish. The 258 had ratios of 8.0, 8.3, 8.5, and 9.2, I believe mostly determined by dish size.

Before I went to the expense of boring out a 258 to try to make more power, I'd get a 4.0 block and build a stroker or source a VAM engine.

[shanebo]

I was going to buy new pistons...Im rebuilding too as well as going with a 4.0 head. The machinist that did the work on my block said the cylinder walls looked fine and a hone was all she needed. He also told me as long as the pistons are solid...no hair line cracks around the wrist pins, gouges ect. buying new ones would not be of much if any advantage to me...If ya got the money new is always better...but if your on a budget ya might want to stick with the stock ones if a bore is not needed and they are in good shape.

[JayRamb]

these are the pistons i ended up going with
http://www.bulltear.com/catalog/product_info.php?products_id=242&osCsid=4534c2622ab952d8ce4d3cb690fa88fe

Bulltear is AWESOME! He saved my 67 Rebel's engine! Keep in mind...this guy has the factory blue prints from AMC! He BUILDS the parts himself! His name is Matt, but he goes by MC.