hi dadtruck, i think this piston post and the pictures will help you. ron

thanks

the Sealed Power brand is Federal Moguls after market name,,
FM has a great reputation for pistons,, but being also an automotive OE supplier I bet they will design aftermarket part structurally, to OE requirements.
I did go with Sealed Power rings, I know that the rings were made at the FM Manitowoc WI plant that I have worked with in the past.
I chose the KB- Silvolite pistons on a belief that they are 100% aftermarket with a racing - high performance back ground company. My guess is their designers would tend to over design for strength..
I think the thicker skirt walls show that.

doug i thought that the metal insert had a different exspansion rate than the surounding aluminum and was undesireable for racing,am i wrong in thinking that? i am using the seal power from summit now in the blower motor and have had no problem , except melting one from a bad tuneup.

I use forged pistons in a true race engine.
I have used a lot of cast w/ steel strut pistons in "street performance" engines with-out problems. (the factory pistons use this design)
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I have seen some "no strut" pistons offered for the SL6 and a few of those with the complete piston top broken-off at the oil return ring groove.
DD

i will have to rethink what i have