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Discussion Starter #1
I've been having problems with a possible vacum leak, which causes rpm's to go up, about 4000 at 70 mph,
I've partially fixed it, and now its down to about 3400 and 70 mph, this seems a little high though, does anyone know what the rpms are supposed to be at 70mph, its a 351c 4v with a c6 trans. Thanks, Dave
 
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Discussion Starter #3
Without knowing the gear ratio of the rear end it is impossible to tell.

Bob White (672nv)
 

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My guess is the slippage in a C-6 or C-4 is about the same. My old '68 with C-4 and 3.25:1 rear gears ran about 3,400 RPM at 70 MPH. Any engine, I-6, 289, 351W or C, etc. would have the same result given the same trans and rear gears.

Numerically lower rear gears would lower RPM's.

Hope this helps,

Russ

http://albums.photopoint.com/j/View?u=1595962&a=12199293&p=44747301.JPG
 

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Also depends on tire size!

http://albums.photopoint.com/j/View?u=1575962&a=11982331&p=43165927.jpg67 Sports Sprint, Convert. Original C code, now 293 ci with Holley 450 and 295,000 miles
MCA #49294
 
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