1970 ls7 heads
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Joined: Jun 2007
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From: Salem NH
1970 ls7 heads
I have a '69 427/435 tripower that has had LS7 heads installed at some point in time. Are these heads a good thing? Are they rare or desireable? I've been told earlier here that the 454 heads on the 427 lowered the compression so you could pump gas. If I was at 11:1 would anyone know about what the compression would be now? Is this a big performance drop? Lots of questions, sorry...Thanks.
Le Mans Master
Joined: Apr 2006
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I have a '69 427/435 tripower that has had LS7 heads installed at some point in time. Are these heads a good thing? Are they rare or desireable? I've been told earlier here that the 454 heads on the 427 lowered the compression so you could pump gas. If I was at 11:1 would anyone know about what the compression would be now? Is this a big performance drop? Lots of questions, sorry...Thanks.
as an example
bore 4.250
stroke 3.760
piston 30 dome
gasket .018 compressed
pistons down .025
compression 11.05
you put on the 119cc chamber heads
the compression drops to 9.83
I dont know exactly what your dome volume is but this gives you a pretty good idea of the compression drop.
Last edited by Little Mouse; Nov 5, 2009 at 11:20 AM.
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From: Salem NH
Thanks for the info. If I could swing a set of the L71 heads the engine should run a heck of a lot better? Do you think the difference would be that noticeable? The LS7 heads don't have a problem revving to 6500.
Hmmm
Hmmm
Drifting
Joined: Aug 2005
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From: League City TX
If you dont you will have to retard the timing to keep it from pinging, and could end up with less power than you have now.
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Joined: Jun 2007
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From: Salem NH
Thanks guys. Getting responses from this forum is the best resource. The more I find out about this car the more curious I get. One cool thing is it came with the HD dual plate clutch. When I took it all apart only one of the 10" discs was there but it still took all the (remaining) torque.
