4 SPD TRANS NEEDED FOR 58

[Don Izzo]

My brother wants to swap out the three speed trans. in his 58 for a 4 speed. Can anyone tell us which trans will be a drop in fit that wont cost an arm and leg. Don't care much about numbers his 3 speed is original to the car and will be kept in storage. just looking for a good or rebuilt easy to swap 4 speed. Don't need a h/p model the car is just for crusing. Thanks!
Don

[Mark S. Lovejoy]

Re: 4 SPD TRANS NEEDED FOR 58

Any Muncie or Borg Warner T-10 will bolt in. You will need to replace the yoke on the driveshaft (I think). The Muncie will need an adapter plate for the rear mount to bolt to (available from all the vendors). Obviously a different shifter.

[John H.]

Re: 4 SPD TRANS NEEDED FOR 58

A T-10 is a straight bolt-in; same length, mount location, and 10/16 input/output spline count as the old 3-speed Saginaw.

[Joe L.]

Re: 4 SPD TRANS NEEDED FOR 58

John, Mark, and Don-----

An original-style T-10 is a direct bolt in. This means a T-10 from a General Motors vehicle of the 57-63 period. The later T-10 (1975+) is not a direct bolt in. For those, a different output yoke and a modified driveshaft is necessary. The Super T-10 (of the same basic configuration as the 75+ T-10) is still available from Richmond Gear. It comes in several different gear ratios and it's really a bargain since you're getting a BRAND NEW transmission of improved internal design. You can purchase one of these NEW for not that much more than a rebuilt original transmission will cost. Keep in mind that rebuilt originals rarely include any new gears.

A Muncie is also a direct bolt it. However, most Muncies will require a different output yoke. 1971+ Muncies will require a different output yoke + driveshaft modifications when used on a C1.

[Christopher R.]

Re: 4 SPD TRANS NEEDED FOR 58

You can either go with a T10 or a Muncie. A T10 was original to your car. Many of them were replaced with Muncies in the 60s and 70s because Muncies were generally considered a better transmission. Chevrolet thought so too. Muncies are generally more availabe than T10s, but there's still lots of T10s around, and lots of them are still in C1s. Remember that these cars don't see the extreme use now that they did then.

But all things are not equal. If you use a Muncie, you'll need a new transmission yoke, about $175. A T10 will take your existing yoke. You'll also use a different clutch disc with the different transmissions, but you'll probably be buying a new one anyway. The T10 will require a mounting adapter - about $10. Finally, you'll be buying a new shifter anyway - about $200, but the linkage rod package is different between the transmissions. With the shifter, you'll need to buy either T10 or Muncie linkage. The only difference is the reverse rod, but I don't believe you can buy that separately.

Point being, while both transmissions will bolt in, there are differences. The decision you make will have cost impacts. Most people, who are not interested in originality, choose between a T10 and a Muncie based on what's available when they go to choose. If I can get a deal on a Muncie from a local rebuilder whom I trust, that's what I buy.

[Don Izzo]

Re: 4 SPD TRANS NEEDED FOR 58

Thanks to all who responded. I found a good used not rebuilt muncie at a local Vette shop for about $500. No shifter or yolk but the shop owner said he can set me up with them.

Don