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Lyn Smith · 01-09-2020, 11:27 AM

The 55 265s and early built 56 265s had flat top pistons, but GM stopped production of them mid 1956. You could not even order them from a dealer from mid 56 on.The part number was discontinued. If you build a 55 Stocker you must use the flat tops, and you must use a cam with 230 or less duration because of no piston to valve clearance. NHRA let the Jr Stockers use the valve relief pistons back in the 60s,and early 70s,but not now.

01-09-2020, 11:27 AM	#15
Lyn Smith VIP Member Join Date: Dec 2001 Location: Pontiac,il. Posts: 1,121 Likes: 217 Liked 841 Times in 156 Posts	Re: 1956 Chevrolet Handyman Wagon The 55 265s and early built 56 265s had flat top pistons, but GM stopped production of them mid 1956. You could not even order them from a dealer from mid 56 on.The part number was discontinued. If you build a 55 Stocker you must use the flat tops, and you must use a cam with 230 or less duration because of no piston to valve clearance. NHRA let the Jr Stockers use the valve relief pistons back in the 60s,and early 70s,but not now.