Could anyone help identify these pistons?

need a pic. also look for a casting line along the piston someplace. it should go from one end to the other. if there is one, it is not a forged slug.

i think it is a cast piston. the valve relief area is rough, and the cross pattern on the side as well. also looks like there are casting lines on the inside of the skirt where the part number is. my opinion.

here is what my pistons look like.

if i had to guess they should be 10.5:1 with your stock heads (around 60-62cc)...

but yes, they are definitely cast-possibly hyper (which are also castings)...you can get away with using plain cast pistons provided you have a good tune, and not too much timing and def no low octane gas.

the old 289 "k" code had 10.7:1 cr with castings as per old Ford tech data...so you can get away with it, but they won't take boost or nitrous if they're plain castings-hyper can however take modest amounts

in addition: If you plan on using these, ck your piston/valve clearance if you're planning on running more than about 0.515" lift (also dependant on how much-if any-the heads or block have been shaved, head gasket thickness, etc...

emagdnim said:

I know they are federal mogul speed pro pistons but im not sure what type , they have B726R printed in the inside of the piston and valve reliefs on one side and a bit of a dome on the other which is suppose to provide 10.5:1 compression (not sure what cc heads) ... Any idea what piston this is? Is it a hyper or forged?
Any idea where i could go for help if nobady knows?

Thanks

Click to expand...

The only way to know for sure is to call the manufacturer and have them tell you what they are based on the part numbers.