#22

02-16-2020, 07:43 PM

b-man

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Join Date: Sep 2002

Location: Sunny So Cal

Posts: 16,461

Quote:

Originally Posted by Jay S

Hmmm....top photo is a w72 piston.

Bottom photo looks like a early 75, from one of the last 988 blocks?

Middle photo is what again? Out of what car???

Is this also a Warsak test?

Middle photo is clearly a 389 piston.

Pictured below are 1964 421 (left) and 389 pistons.

The 421 used larger valve reliefs to lower compression and match the compression of 389 engines, much like how 428 engines used dished pistons to maintain the same compression ratios of 400 engines while using the same cylinder heads.

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1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/2.56
2002 WS6 Convertible LS1/4L60E/3.23

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