Beave

Well after 160,000 miles and hundreds of passes in the 11s my stock trans took a dump. After reading and reading and pricing 4l60 builds I realized I could just do a brand new built th350 setup for the same price and have a trans that actually holds up. My question for guys who have done the same is how much different is the drive ability with the 3 speed? Its not a daily but I still drive it a lot, to and from the track etc. My dad always had chevelles, novas, malibus etc with th400s and it seems like he barely ever had trans issues running 10s in a street car. Of course that was before I could drive and ive never actually driven a car with a 3 speed auto and loose converter. Im hoping I can still drive it anywhere but some ppl have warned me saying its going to be a pita compared to how it drove with the stock trans. As long as it runs good at the track and holds up that's the main concern but Im hoping to hear from people who have th350 say its no problem and they love the way it drives! lol, thanks for any input.

Here is the setup Im going with-
PTC th350 with upgraded clutches, drum and 36 element sprag
and deep pan
PTC 4000 10" converter

Raoul-Duke

iTrader: (6)

In for information as well.

lemons12

iTrader: (71)

Im a ptc nut. Only converter i run. Bought 4-5 in the past year.

I won't run a ptc transmission.

Stop and go won't be much different. 50-60+ for extended amount of time Will suck.
Rear gears tire and converter Will play a large roll.

redtan

iTrader: (5)

Depending on your gearing and exhaust setup, you might go crazy driving for extended periods of time on the highway.

My exhaust used to be loud, and it sucked driving on the highway at 2000rpm. I can't imagine what it would be like doing that at 3000+ rpm

nj02z

iTrader: (6)

What you would save on the trans you will spend on fuel and wear on the engine with the increased rpm at cruising speeds.

lemons12

iTrader: (71)

Increased rpm does not wear the engine.

With a steeper gear the engine isn't working as hard.

And just because its bad at 2k rpm doesn't mean the exhaust Will be bad at 3k. I have horrible drone and its loud from 50-about 58mph.. From there up no more drone and quiets down.. The entire exhaust tone changes.

brokenfly

you now can experience time travel.
just add some bias ply maypops and drum brakes to feel what we old fellas put up with back in the day.

01WS6/tamu

iTrader: (37)

You will experience awesome reliability in your future. Back when gm built a solid tranny that could take a beating.

Kingc8r

iTrader: (21)

I too have been considering this swap. I have two track by me, the more lenient one is 100 miles away.

I love the driveability of the A4. I could go 4L80 but that's super expensive.

My car will be a weekend warrior at best. I'm thinking it's best to swap to a 3 speed for longevity since I plan on racing a lot. My friends want me to keep the A4 as they think I'll hate the A3.

I'll be following this thread for sure.

Lemons why don't you like PTC Transmissions?

zracer323

iTrader: (12)

For an 11 second car I don't see much of a point of switching away from a 4l60e. The 60 definitely has it's flaws but building it to handle that amount of power is not hard.

mjs1012

iTrader: (36)

This is what I was thinking as well. A built FLT or RPM 60e should last a while unless you are dead set on doing the swap or plan on more power.

Kingc8r

iTrader: (21)

Well if you're HCI and your setup is optimized you should be bottom 11s/high 10s.

Then if you add spray you're SOL unless you have a $2300+ 4L60. Even then from what I've read people whole race their car often usually have to do a rebuild after a couple to few seasons.

thunderstruck507

iTrader: (18)

You couldn't pay me to go back to a th350 or th400 in a car I wanted to drive much. Especially not one with a high stall converter.

I wouldn't even want to lose the ability to lock the converter in the 4l60e on the highway.

If you want to know what it's like it's not hard, jump in a car with a 4l60e and put it in 3rd and set the pcm to not lock in 3rd gear. You will be at 3000rpm or more a lot.

Beave

Well I did the swap yesterday and to be honest I love it. I only drove it a few miles so far but its not that bad and I actually prefer how it feels going from a 3200 converter to a 4200. I never really drive faster than 60-65 on the highway and like I said its no longer a daily driver. The converter is pretty loose so you never feel or hear it shift gears when running in drive, it just sound like it has one speed lol.

PBA

The TH350 when that first came out were considered junk, just the same as when the 700R4 first came out. Within a few years of their introduction, the transmissions were starting to hold up to some horsepower and were proving to be very durable when the right parts and torque converter were used. To me the 4L60E has proved itself to be a better transmission than the TH350 when setup correctly, and have the benefits of the "overdrive". I was driving 11 & 12 second vehicles back in the 1970's and would have loved to had the 2004R or the 700R4 back then when running 4.33's through 4.88's on the street. The gas mileage was not good and the noise.... Stick with the 4L60E and stall of your choice or in my opinion, you will regret it.

Beave

Well I know this particular trans is good for 700whp. I will be racing the car more and driving it on the street less so that's why I made the choice to do the th350 as I know it will hold up better than any 60e. I couldn't justify paying the same money for an entry level 4l60e (from a reputable shop) as it would cost to get a th350 with all the upgrades and a brand new converter, esp knowing the 4l60e is still a ticking time bomb unless you go all out which costs double what the th350 would. I do appreciate everyones input on this and now im just ready to hit the track and see what she does!

Beave

Exactly! My car will be in the 10s on motor with the changes ive made and if it doesn't it certainly will with the new cam ill be putting in. Then I would like to add a 100 shot once ive got in the 10s. I have seen too many guys with fully built 4l60e's put $2500+ in them and they wind up breaking within a year with roughly 500whp in a 3500lb car.

Beave

Well just wanted to update you guys. Drove the car to the track (60miles) made my 4 quickest and fastest passes to date and drove it back home no problem. 60mph is the optimal cruising speed now which im fine with. My only question is why didnt i make the switch sooner lol.

nj02z

iTrader: (6)

What rpms at 60 mph?

DietCoke

iTrader: (18)

A 350 and a 4l60 are more or less the same internally as far as clutches and power holding parts go. Just like the 400 and 4L80 are more or less the same. Dumping a 4l60 for a th350 for some kind of strength gain seems silly. They're lighter, smaller, less parts, so naturally cheaper. You also dont have to deal with the OD circuit.