Ranzan

hey guys starting to dig through my engine stuff seeing if I need anything for the build

I bought a 400 and 455 a few years back as a package

info that i was given is block is done other than final hone 30 over
crank is finished off at .20 and .20 with machine tag still on it

i am no motor guy so i need help with these pistons .... are they good bad no name brand and so on

IMG_2309.jpg
stamped 30 over


IMG_2310.jpg
they have stock rods on them but other than that I know nothing about these

Rickman48

If they had an F stamped on them, they'd be forged, otherwise they're stock cast iron.

cutlassefi

Pistons are forged, rods look forged, didn't think Olds made anything other than forged rods for 455's. Don't think they did.

InfoJunkie

They are SpeedPro/Sealed Power forged pistons for a 455. They are a good brand.

Ranzan

thanks guys for the info
so would these be stock compression pistons with no dish on them?
one other thing I noticed they have some stuff marks on the skirts does this effect them in anyway? I wouldn`t think so but....

InfoJunkie

They are stock compression ratio with a dish.

The side you show looks fine. Are they "stuff" (what kind of stuff ) or scuff marks.

Ranzan

lol scuff.... my bad

64Rocket

Post some pic's of the damage area you say on the pistons.
If they are scuffed, you will need to measure the skirts, to make sure they are all in spec. If they are usable you need to make sure you have .005 piston to cyl wall clearance, when you assemble the engine .
If they are scuffed, the reason is that they were to tight in the cyl. That why i say .005 clearance.

Gene

svnt442

Guys TRW made 2 versions of these pistons 20 years ago both cast and forged. These are cast, not forged, due to the missing "F" in the part number. I opted for these when I put my engine together in 1993 because I couldn't afford the forged ones and I didn't see the need for them when I put the engine together.

cutlassefi

That's the nicest looking cast piston I've ever seen. Ranzan can you give us a pic from underneath?

507OLDS

I had a set of those in the early 90's.Mine were forged,and they looked just like the ones pictured.

Ranzan

Gene thanks for the info that is good to know

i will take some pics of these and post them for you guys

like i said I will have to take the block in to get checked over to make sure everything that was said to be done has been done
but it will be good to know where i stand before hand with the rest of the stuff

InfoJunkie

I remember when Speed Pro pistons were numbered without an F. I had an old catalog and a customer told me his engine builder said he needed forged pistons . He gave me the number on his pistons and I looked it up.
Behold he already had forged. It was about 20 years ago when they made the change. I have never seen a cast piston with that little circular mark in the middle but I've only seen a few hundred sets. I know there are people out there who have seen thousands and there is most always an exception to the rule. I'm not saying your wrong or trying to argue the point. I'm just trying to explain where my answer came from.