Man to Auto Tranny swap

[Krafty]

Hey guys I've got a 81 300 with a manual 4 spd tranny, now I need to know if I can put a c4 from a 79 302 2wd car in its place, I have the column to swap out for the shifter. whats this I hear about the output shaft needing to be changed, why is that? thanks

 

[vincendebbie]

Hey guys I've got a 81 300 with a manual 4 spd tranny, now I need to know if I can put a c4 from a 79 302 2wd car in its place, I have the column to swap out for the shifter. whats this I hear about the output shaft needing to be changed, why is that? thanks

The output shaft going into the transfercase is longer than the one that is in the 2wd tranny. --Vince

 

[Krafty]

Do you know if I can use to one out of the manual tranny or do I have to get an automatic specific output shaft?

 

[92bronco_in_progress]

Do you know if I can use to one out of the manual tranny or do I have to get an automatic specific output shaft?

you need one out of an auto trans......u might wanna get one out of a 4x4 because you need to tear apart the whole trans to get the output shaft, everyone else is going auto-manual swap, and your doing a manual-auto swap.......why?

 

[Krafty]

cause my fiance hates it. it didn't help that when she was trying to learn how to drive it the tranny mount broke, so she has very little patience for that truck. So by doing some convenience upgrades then I don't have to buy a new truck there by saving about $12 000

 

[Yardape]

It would be alot easier to change her mind than do that swap. But if you do your much farther ahead to get a tranny out of a 4x4. That way the linkages should be the same, you will need the tranny lines. Another thing to keep in mind, you will need a flexplate and I havent seen very many 300 I6's with an auto so I do not know where you would get one.

 

[Ogeechee 4x4]

Another thing to keep in mind, you will need a flexplate and I havent seen very many 300 I6's with an auto so I do not know where you would get one.

Your local parts store can get them for you.

 

[Krafty]

Your local parts store can get them for you.

I know that I can use the flex plate off of the 302 I am getting the c4 from. 300 autos use the same tranny combos as the 302 v8s and the parts go back and forth

 

[Yardape]

Goodluck with the balance. Even though it will bolt up, the 302 and the 300 will be balanced differently

 

[92bronco_in_progress]

Goodluck with the balance. Even though it will bolt up, the 302 and the 300 will be balanced differently

much differently......its two completely different style of engines......your gonna have to buy a new one or the balance will be way off and you'll be looking at more than a tranny swap

 

[Justshootme84]

Krafty, do you already have the C4? reason I ask is that is a 2wheel drive, car tranny and will be very hard to convert to a married 4WD t-case. Not only would you need to swap the output shaft, you'll also need to find a tranny to t-case adapter. One from a C6 auto may work if the bolt pattern is the same as the C4, but I don't know that for certain. The C6 will be much stronger and able to handle the torque from the 300I-6. You should be able to swap the C4 for a 4WD C6 or find one for less than $400 (US). You can still use your transfer case with the C6, but will need to use the shifter linkage from a C6, IF you used the C4, you'd have to modify the linkage to fit it since none is available. Your stock radiator may have fittings for the tranny cooler lines, or you can just add an auxillary one. You'll also need a vacuum source for the C6 modulator valve, and hook up the tranny kickdown from the carb. JSM84