Are there any major negatives with the early C4 trans?

[sparx]

I began reading on rebuilding the C4 trans and after talking to an old timer trans guy today I found out the early C4's had a mode for wet or icy conditions.
My car is a 66 so it has the trans with the green and white dot on the shift selector. This he mentioned was changed in 1967.

Since my car never ran I had no knowledge of this. Other than the C4 not having an overdrive is there any reason to not rebuild or have it rebuilt?

I thought I had read somewhere these were not good -- not completely sure this is fact.

sparx

 

[109jb]

The C4 is a good transmission and can be built to take loads of horsepower. There are a lot of aftermarket upgrade parts available. A lot of drag cars use the C4 because of this. IMO, the lack of overdrive is the only drawback to the C4.

 

[brianj5600]

Most people swap to a 67-69 valvebody on those. 69 and older C4s use a smaller input shaft too. Jay at Broader performance recommends 70+ input shaft and drum if you go much over 400hp.