Topic: correct RPM?
in Forum: C3 Engines
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West Bend, WI - USA
Joined: 3/18/2010
Posts: 46
Vette(s): 1985 silver coupe & 1975 red coupe
I have a 1975 Vette which I just got on the road after much work. I installed a GM 330 HP crate motor and had the TH400 trans rebuilt and beefed up. The car runs great but what worries me is the engine RPM. At 70 MPH the tach shows 3500RPM. The rear end should be a 3.36 gear. Does this engine RPM seem high to you guys? Maybe I should have went with a over drive transmission as was suggested. Please advise.
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Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
What size rear tire do you have?
My '74 has 3:36s, and it tachs right at 3200 rpm at 70.
My '74 has 3:36s, and it tachs right at 3200 rpm at 70.
Joel Adams
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Lifetime MemberEquinunk, PA - USA
Joined: 10/31/2007
Posts: 2465
Vette(s): 1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.
I have 3:36s as well. I'm Tunin bout 3g at 70 with G-70s
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
2023 Accelerate Yellow HTC Stingray
3,200 @ 70 w/ 3:55 gears and 255/60-15 tires
1973 L-82 4 spd
in Forum: C3 Engines
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