gmmusclecarman

iTrader: (20)

Not sure if this is the right place for this but whatever. Anyway ive got a 98 Z with a built 408 and 6 speed. Currently on the stock rear with 2.73 gears. Ive got a 246/254 custom cam and TFS 235cc heads. I was getting 14.5 mpg with half city half highway and beating the hell out of it. now im getting 11-12 all city with beating on it. Does this sound normal for what i have done? not sure what to expect with this setup....

Unertl42

iTrader: (63)

it should get better highway, but you'll get more answers in the "Gen IV External or Internal" sections

xdanny510x

at first in my truck i was getting only 6mpg when i had 408 barley installed.. but after driving on the highway and breaking it in im getting 12 mpg

Z-28

You need better gears with that combo. Maybe then u get more mpg.

speedsk899

Who cares if you are building stroker motors!

gmmusclecarman

iTrader: (20)

Workin on getting a new rear end with the right gear ratio.

DaveX

Sounds about right for around town. Lower gears might help a little but I wouldn't expect it to pick up all that much. I'm getting about 13 around town with my mods without putting my foot in it all the time. But that's about the same as my factory silverado.

allngn_c5

iTrader: (3)

t56 with 2.73's ? Shouldn't it be 3.42's ?

Anyways with my 402 m6 with 3.42's gets 27mpg on the eway if you are setting the cruise control. Hot rodding or light to light, she sucks it down. Single digit lol.

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