What gear to go with
Thread Starter
6th Gear
Joined: Jan 2011
Posts: 6
Likes: 0
What gear to go with
I have a 74 vette that i am building a 406 for, i am wondering if i should change gears or leave the 3.08 in. The car is stock now with the 350 and wont even think about spinning a tire. I realize by putting in more power it should get a lot better, but i don't want to put in more motor and have the same problem. Should i put a larger stall converter in and stay with the 3.08, or change the gears to 3.73 and stay smaller with the converter? The engine with be 11:1 compression with sportsmanII heads with solid flat tappet cam with auto trans.
Instructor
Joined: Sep 2011
Posts: 164
Likes: 0
From: Columbia South Carolina
the gear you choose and the converter you get have to be chosen with the cam/compression of the motor. if you build a lower compression motor with a short duration cam, you can probably use a stock converter and gear since that 406 with good heads will make a load of torque. longer duration cam requires a higher (numerically) gear and higher stall converter. rear tire diameter is another consideration when choosing a gear.
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
With a hot cam and auto trans (assuming TH350) you definitely need a converter and gears if you really want to maximize your off the line acceleration using drag radials. If you just want to burn up your street tires then it won't matter much with the 406.
Melting Slicks
Joined: Feb 2006
Posts: 2,209
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From: Mo
i think a 2500 - 3k stall and a 3.42 or 3.55 gear would work best.
Might as well go roller cam to little more money but less problems later, getting a flat tappet cam to live with todays oils are near impossible
Might as well go roller cam to little more money but less problems later, getting a flat tappet cam to live with todays oils are near impossible
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Choose a converter appropriate for the power range of the engine. Then drive it with the 3.08 gear and see what you think.
A lower gear will obviously improve low RPM acceleration, but a torquey engine and a good converter may be enough to make you happy.
A lower gear will obviously improve low RPM acceleration, but a torquey engine and a good converter may be enough to make you happy.
Thread Starter
6th Gear
Joined: Jan 2011
Posts: 6
Likes: 0
I have looked at roller cams but for the money invested i think i can make really good power with a solid flat tappet cam. The roller will last longer and be maint free but with the proper additives the flat tappet should be fine. What is everyone going with solid roller or hydraulic roller, also what brand is best for the money?
