I had a valve seat break.. pulled the heads cylinder walls still look great.. it only ran for maybe 5 seconds like that.. so my question is since the cylinder walls look great im just gonna replace the piston since its got some minor scarring on the top. I pulled the heads off and ive only got a weird E symbol and the numbers 1212 0307 written on the top. It is a flat top piston with 4 valve reliefs.The motor was rebuilt by previous owner about 30k miles ago and the retard reused the heads without having them cleaned up or anything.. 160k miles on them. So My question is ive read around that alot of people rebuild lt1's with a SBC rotating assembly.. is there any way for me to find out if its balanced for SBC or LT1. I was trying to identify the pistons figured it would give me an easy answer but no luck online.. The block has a red tag with a remfg number on it. Havent seen anything other identify marks on it. Any help Would be greatly appreciated.. might just have to pull shortblock take it to machine shop just figured id ask first..

thanks

corey

 

All SBC with a one piece rear main seal are externally balanced from the factory. Regardless of what it is or what it goes in.

pistons look like these?

 

all i can help you out with is that the red tag you see is to show the rebuilder that it didnt overheat, in case there was a warranty claim. the tag is designed to fall off once the motor gets too hot. if the tag is not in place and you have a problem, the rebuilder will probably do their best to deny a claim. too bad you cant contact the person you bought the car from. if they are helpful at least you can get a shop name.

 

so if i buy a piston for a once piece main SBC as long as its .40 over and flat top with four valve reliefs it should fit? also, all the pistons ive seen used pins.. will the pin just come right out and the new one go right on for connecting the rod??? Or is this something i will have to take it to the machine shop and have them do on a press?

 

http://www.summitracing.com/parts/STL-WH345NCP40/


this work?

 

Take the rod/piston to a machine shop(the one that's fixing your head?) and have them replace it for you - the pin needs to be pressed out and the rod heated to put it back it. They will need to weigh the piston to check if it is the lighter weight LT1 piston or if generic SBC pistons were used.

 

I see in your sig your running nitrous. if you have the engine this far apart anyhow Why not replace all your pistons with some forged ones instead of taking a chance on trying to replace one unknown piston.