Indian-giver

I have a 78 L82 automatic car. I really want a 4 speed. How involved is a conversion. The car has 38K miles, would the conversion hurt the value much or would I be better off selling it and finding a 4sp car?

oledave60

I just finished a th400 to M20 swap and I love it. It puts the fun back into driving.

The swap is pretty involved but if a 76 year old can do it anyone can. You need to do a lot of search and research to get an idea of what is involved. Then start getting the parts that you need other than the trans.

I think a 4speed improves the value, but who knows. I will try to make a list if you get serious.

John Ulrich

Go 5 spd

keithinspace

I'd agree...for all the pain, suffering, cost, and effort, I would spend a few more bucks and get a 5-speed.

It will allow you to go crazy with the rear gearing and pick up a significant performance gain versus the 4-speed.

oledave60

I did not do this swap for gas mileage, but for the fun of driving,. Five and six speeds are just like an automatic./

cagotzmann

Here is my 78 conversion (T56 magnum 6 speed)
https://www.corvetteforum.com/forums...-corvette.html

Before this update I compared 4 speeds vs 5 and 6 speeds for shifting quality. I also have driven many C6 corvette's at the track, and after driving C6 6 speed's all the C3's with 4 speeds shift not to my liking at all. Very poor down shifting etc.

After the conversion I went back again to test 4 speed cars and they shift like 70's car, nothing like the modern cars. I think my 2003 VW Jetta 5 speed shifts better than the C3's 4 speeds.

But many like how old tranny's shift. I suggest you test drive a C6 and a C3 and see which you like better.

My T56 Magnum shifts like the C6 cars. ( I used a hydraulic clutch system)

Priya

I can't imagine how you figure that.

LT1M21Vette

74Ken

My first question would be did you mean a swap to a 4 speed manual? or an automatic with overdrive?

I want to do the automatic conversion, a lot simpler.

Ken

donnie1956

This swap is not for the mechanically challenged.
I completed the auto to manual swap a few months ago. I swapped a tremec 5 speed. Biggest challenge for me is I have an LS engine. The z bar was a pain but I got if figured out. You will be pulling the dash apart. Pulling the old pedals, Moving the brake booster, pulling the steering column. Mounting new pedal assembly, Mounting the z bar and linkage.
As far as value the 78 unless its a pristine pace car, it isn't worth much anyway. You can probably find a manual car cheaper than doing the swap after you have rounded up all the parts.

Priya

I don't think the decision is as straightforward as that. Do you like the colour of your present car and its options, or would you like something different? If your car is in good condition are you going to be able to find one easily in similar condition, you risk getting one with hidden problems. Are you okay with a 4 speed or are you going to find as I did once you get the 4 speed you'd really rather have a five speed? If so it will be a lot harder to find a 78 in good condition with the colours and options you want that has a five speed already in it. Depending on your answers to these questions it may be worth the extra cost to put a 4 or 5 speed in your current car.

oledave60

The purpose of my post was to get a C3 back to fun driving, not to get it to ease of driving. If you want silky smooth shifting, no pressure clutch , and no rpm"s you should just get a stick Honda with a fart can muffler.

Priya

Yeah, I'm just not following you.

73 Scott

Me either, I just did a 4 speed yo 5 speed swap. Forth gear even with 3.36 gears is still 3k rpm on the highway. Plus the 5 speed has a lower first gear so it feels like another 100 horsepower. The when you hit the highway hit fifth gear and you're getting over 20 miles to t he gallon. If you want it to be more fun to drive the 5 speed is the way to go.

Priya

If you've got an auto and want to convert to a manual I can't see why you'd take a 4 speed over a 5 speed.

myoriginal77

I have a T56 - 6 Speed - 4:11 gear - best of both worlds - I'm out of 1st in about 3 seconds but no import can catch me off the line and then in 6th on the highway I'm cruising at low RPM.

Happy Motoring,

Frank

73 Scott

I could see an old school guy wanting a four speed because they shift differently. You can hold the gas to the floor, tap the clutch and slam gears with a four speed. You can't do that with a 5 speed, they just won't do it. I don't care though, I don't drive like that anymore. Four speed is cheaper as well. A good five speed is a couple thousand more by time you're done. IMO in the later cars it increases the value though.

red topless gator

Donnie, you forgot to mention the need for a lot of muscles.

cv67

If anything I bet the OD will increase value

Selling a car you like just to have a 4 spd doesnt compute to me but hey to ea their own as said these arent rare or collector cars anyway even if they were you want what you want

At least you know what you got now thats worth something

Make the car fun to drive who cares about what some guy down the road might or might not want? Live for yourself!

Priya