318 stock pistons

[Double Six]

I have a 69 318 that I am going to beef up a little. I see no oversize markings on piston tops but they have 4 valve reliefs are these stock or has this engine been built before? I haven't had a chance to mic cylinders yet. thx, Double Six

 

[moe7404]

my 1967 dart, coronet, charger factory service manual. shows the stock 318 piston with 4 valve releafs in the top. factory over sizes .005" .020" , .040". in the past i have seen .010" over size from the factory in a 440. and no after market pistons come in .010 over eather. but the .010 oversize is NOT available from the factory over the counter.. ill guess the ,005 oversize is NOT available ether.

 

[txstang84]

Run the engine to TDC and measure the piston to deck height...that'll tell you if they're stock '69 vintage or aftermarket...as per some other members research, they are the tallest stock 318 pistons. They're only .030" in the hole.

 

[Double Six]

thanks guys I appreciate it , Double Six

 

[pishta]

4 brows is stock, one casting for both sides...cheap! Badger usually has some cheap +.010 available. That +.005 is odd, what do they hone it with, a dingle-ball?

 

[krazykuda]

Yes, they had 4 brows in the 318 pistons in the late 60's.

 

[A38Valiant]

68 and 69 pistons have 4 valve reliefs, and were 9.25 compression with open chamber heads. 67 also had the valve reliefs and 9.25 CR, but used closed chambers.