Tranny

[micon]

New motor going in to 73 with c4 auto. Hp should be around 400hp. Can stock c4 handle it. If not can I get it modified or replace?
if replace looking for suggestions. This is my driver.no racing.

 

[Broncobowsher]

A C4 can handle that just fine.
Now weather your C4 can handle it, or if it is on the end of its life right now will be hard to say. You are asking if a 50 year old automatic of unknown mileage or condition is going to survive? I can't tell you if it will make it around the block with the stock engine.

 

[micon]

A C4 can handle that just fine.
Now weather your C4 can handle it, or if it is on the end of its life right now will be hard to say. You are asking if a 50 year old automatic of unknown mileage or condition is going to survive? I can't tell you if it will make it around the block with the stock engine.

Tranny was rebuilt about 4 years ago. Maybe 10,000 miles since. Used as daily driver.

 

[bigmuddy]

My answer is it will likely be fine unless you hammer on it consistently, then it likely going to need upgraded internals sooner rather than later.
Mileage may vary depending on drivers inputs as buddy used to say..

 

[pcf_mark]

A torque converter upgrade may also be needed for you cam choice which would also make me recommend a trans cooler upgrade. Assuming the trans is solid already that is.