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I'd use them if I could keep my L-2349 Pistons. That extra CC would drop the compression.
If the old closed chamber heads froma '66 396 work, can't see why these won't work. I have one original 820 left.
820 LS5 head chamber.jpg 820 '71 LS5 454 castings.JPG
From a Chevelle club: "The 820 heads were used on the 1971 Corvette LS5 engines and are a good head to start with. Someone flowed ALL the production cylinder heads on EVERY engine and listed all the findings. And I think the 820 heads had the largest oval intake port of all the BBC ovals. Somewhere there's a link to that list but I haven't been able to find it."
From Nasty Z28.com: "The 820 head is an open chamber* however it is not shaped the same as the hi-perf open chamber heads such as the "990" castings. You would use a closed chamber piston with a small/moderate dome. I ran a 396 +.030 back in the 1980's that had TRW L2242 +.030 forged pistons. (.335 dome and 11 to 1 comp. with 109 cc closed chamber heads).
I see they still sell L2242NF pistons and L2328NF pistons thru Speed Pro. These would put you around 10 to 1 comp. with a std. Fel Pro composition head gasket.
I should add that I have owned a couple different BBC with closed chamber forged pistons and the open chamber* (non "990" castings). The 427 I had was TRW L2268 std. piston equipped and there was NO dome to chamber interference."
If the old closed chamber heads froma '66 396 work, can't see why these won't work. I have one original 820 left.
820 LS5 head chamber.jpg 820 '71 LS5 454 castings.JPG
From a Chevelle club: "The 820 heads were used on the 1971 Corvette LS5 engines and are a good head to start with. Someone flowed ALL the production cylinder heads on EVERY engine and listed all the findings. And I think the 820 heads had the largest oval intake port of all the BBC ovals. Somewhere there's a link to that list but I haven't been able to find it."
From Nasty Z28.com: "The 820 head is an open chamber* however it is not shaped the same as the hi-perf open chamber heads such as the "990" castings. You would use a closed chamber piston with a small/moderate dome. I ran a 396 +.030 back in the 1980's that had TRW L2242 +.030 forged pistons. (.335 dome and 11 to 1 comp. with 109 cc closed chamber heads).
I see they still sell L2242NF pistons and L2328NF pistons thru Speed Pro. These would put you around 10 to 1 comp. with a std. Fel Pro composition head gasket.
I should add that I have owned a couple different BBC with closed chamber forged pistons and the open chamber* (non "990" castings). The 427 I had was TRW L2268 std. piston equipped and there was NO dome to chamber interference."
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