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Old 02-09-2013, 04:39 AM
GreenLS6 GreenLS6 is offline
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Default Re: Higher value 69 Chevelle COPO 427 or L-78/L89?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Postsedan</div><div class="ubbcode-body">Tim,

Tell us ALL how much SLOWER the LS6 is compared to the L89 Post Sedan Chevelle [img]<<GRAEMLIN_URL>>/[/img]

Dan </div></div>
My LS6 is no slouch .I certified the LS6 - factory GM cam ,advertised comp. 11.25, no porting AT ALL.
Cam and carb are actually to small for the LS6 (SAME cam 396-427-454). ALL done makin power by 6200. I pick up 1 1/2 mph going to a 850cfm and pulls to 6500.

396 takes advantage of the NEW Pure stock rules with 1.5 over stock compression (12.5)with 50 less Cubes the factory cam retarded 3* degrees and 780 pulls<span style="font-weight: bold"> hard </span>to 6800 rpm. Same cam-same carb. Better utilized.. Also ZERO porting .The post car is 500lbs lighter with L89 heads and Deleted options. Only down 20 hp on dyno but allows to launch harder without blowing the tires! Less mass, lots power- goes vrrooomm.. [img]<<GRAEMLIN_URL>>/burnout.gif[/img]
Take Erics 396 dyno Build, add 1.5 compression,retard cam,I went threw 60 rocker arms to find the Most lift,and tune to a razors edge. [img]<<GRAEMLIN_URL>>/naughty.gif[/img]
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Tim Clary
68 RS/Z28
69 Olds Cutlass S
70 Chevelle SS LS6
70 AMX 390 Go-pack
71 Torino GT 429cj
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