bedajo32

Thanks for any thoughts

Dropping in a new 383 in my 71 vette. I currently have the original 350 automatic.

The new engine is going to have around 450HP so should i rebuild my current trans to handle that or buy a new one?

if so any recommendations on a trans that will fit in my car and work with a SBC 383 crate

thanks!

Easy Mike

If your tranny is original, it should be a TH400.

bedajo32

yeah I know that, just meant that the engine is a 350

lakerider57

I also went to a 383 stroker with similar horsepower and have an auto tranny and I decided to just rebuild it.

You can make it more stout by adding hardened sprags/races and add the TransGo shift kit.

Richard

bedajo32

thanks for the insight. When you put in the new engine did you have any vacuum issues?

lakerider57

I'm not that far along. I'm doing a body-off restoration so I'm working feverishly on the components in the engine compartment so I can mate the two back together.

I don't anticipate too many vacuum issues since I'm converting to electric headlights and getting rid of cruise control, so I only need vacuum for tranny, power brakes, and AC/heater controls I believe.

Also, my cam is fairly mild to make the car more streetable.

Richard

calwldlife

the ole preventative maintenance
question.

i would consider an overdrive tranny.
and if not i would have it built with better
parts.

new engine deserves the peace of mind of a good tranny.
now if it was a stock deal and time and money were in play,
i would have to evaluate the orig trans for milage
etc.

suprkoop

I did it just the opposite, went from an auto to a 5 spd Tremec so I figured it needed a new motor. Got a crate motor, new 5 spd trans, all new brakes master cylinder to rotors including lines, new p/s pump,cylinder and lines, so the only thing that can fail me now is the rear...ha..ha...right..

lakerider57

If it helps in terms of you making a decision, I rebuilt my TH350c with TransGo shift kit and hardened parts with all the internals rebuilt and including a new torque converter for around $800

Richard

bedajo32

thanks for responses.....I think I am going to just do a rebuild. Money isn't the biggest thing for me it more about reliability and performance. I have had this car now for 7 years and in that time I have run into a few times when putting on new parts that they say just fit right in never goes that easy. I figure just having it rebuild with top of the line parts is the way to go .

UNLESS...someone here knows 100% of a new one that will fit perfectly and handle the performance and reliability i want

ENCSDOUG

I'm running a 383 stroker pushing a little more HP and using the original TH400 with no issues. Make sure you match your motor with a good stall converter. I'm using a 2800 stall in mine. Good luck!

Street Rat