M6 to Th350 or Th200r4 swap

[ThreeHonks]

If you are going for absolute strength, go wiht a 400 hands down. A 350 is really not that impressive, even when built. If you are going to go with a weaker trans to start with, why throw OD away?

[1BADAIR]

franciss car has never broken a th350

[bri2203]

700r4 is a mechanical 4L60e. No difference in strength.

Im always on the "go big or go home" end of this subject. TH350/400 ftw. If you want you can pickup that one todd is giving away on this board... im probably not going to have time for it.

Agreed. "4l60E is basically the same as a 700r4, but it does not have a throttle vavle cable or conventional valve body. In a 700R4 a cable operated throttle controls the internal transmission pressure and shift points."

It sound like you want what what every body wants. The best of all words for a couple hundred bucks. I think you should think long term here. No offense but it seems like this is one of your first builds. I would strongly suggest talking to others, thinking long term with your goals in mind, what rear end you will go with, if you will install a cage etc.

If you are going for absolute strength, go wiht a 400 hands down. A 350 is really not that impressive, even when built. If you are going to go with a weaker trans to start with, why throw OD away?

x2 IMO the best(not the cheapest) choice is a turbo 400 with a gear vendors overdrive. They will handle over 1200 hp and there are many 7 and 8 second cars with that setup.
A 350 can be built to handle quite a bit but the 400 is stronger. The drivetrain loss is slighty different and 1st gear is slighty different but neither are enough to make a noticable difference.

[mtuggle86]

If you are going for absolute strength, go wiht a 400 hands down. A 350 is really not that impressive, even when built. If you are going to go with a weaker trans to start with, why throw OD away?

Thats a good point on the overdrive. From what Ive read a 4l60e in good shape with a aftermarket trans cooler and shift kit can handle 400rwhp so maybe going with that would just be the best choice overall i was under the impression that they where weaker then that even. Now can anyone give me some more info on it swapping a 700r4 in would work just as well Im really not liking the thought of having to change the wiring harness.

heres the 700r4 i was looking at on sale-33rwe-1796656203@craigslist.org

[1BADAIR]

http://www.speartech.com/

[JoeliusZ28]

If you are going for absolute strength, go wiht a 400 hands down. A 350 is really not that impressive, even when built. If you are going to go with a weaker trans to start with, why throw OD away?

from what I have read, even the TH350 is substantially stronger than a 4L60e.

another thing to consider (and another reason I like the TH350/400) is a taller first gear ratio. The short gear in the 4L60e seems to be designed for lower power vehicles to help generate some off-the-line torque...whereas a high-power car is going to blast right though that. A taller first gear will be more useful and also means you get a shorter jump to second. And I think the taller first gear is the reason many cars will do a couple tenths better in the quarter mile after swapping from a 4L60e.

[ThreeHonks]

And I think the taller first gear is the reason many cars will do a couple tenths better in the quarter mile after swapping from a 4L60e.

couple tenths in the 1/4 vs. OD and better streetability/mileage. I'll take the OD 8 days a week.

A 4L60e can be built to handle some serious power. But it takes $$$. Most people wont run the $500 GM 5 pinion planetary gears, etc. etc. I have no hesitation about the 4L60e. If I was going to build an all out track car, then yeah, it would be replaced with a 400.

[1BADAIR]

4l80

[JoeliusZ28]

couple tenths in the 1/4 vs. OD and better streetability/mileage. I'll take the OD 8 days a week.

A 4L60e can be built to handle some serious power. But it takes $$$. Most people wont run the $500 GM 5 pinion planetary gears, etc. etc. I have no hesitation about the 4L60e. If I was going to build an all out track car, then yeah, it would be replaced with a 400.

Thats $500 id rather put towards an 80e and have both

[mtuggle86]

Agreed. "4l60E is basically the same as a 700r4, but it does not have a throttle vavle cable or conventional valve body. In a 700R4 a cable operated throttle controls the internal transmission pressure and shift points."

It sound like you want what what every body wants. The best of all words for a couple hundred bucks. I think you should think long term here. No offense but it seems like this is one of your first builds. I would strongly suggest talking to others, thinking long term with your goals in mind, what rear end you will go with, if you will install a cage etc.





x2 IMO the best(not the cheapest) choice is a turbo 400 with a gear vendors overdrive. They will handle over 1200 hp and there are many 7 and 8 second cars with that setup.
A 350 can be built to handle quite a bit but the 400 is stronger. The drivetrain loss is slighty different and 1st gear is slighty different but neither are enough to make a noticable difference.

Your right I think I jumped the gun on the th350. Im looking to have a street car that I can run a maybe a high 11 andhave fun with and then drive home. My car is only around 400rwhp and I dont have any plans to make more power anytime soon so after reading I dont think theres any need to swap to a th350 at that power level given the fact you lose OD. I think a lightly built 4l60e and stall is a better choice for me although Im really not looking forward to swapping the harness if I swap them.

#1 If I switch to an auto part of the reason will be to keep the stock 10 bolt rear end with an auto low 12's high 11's shouldn't be a major issue on the 10 bolt yes I know it could still break but there are 10 bolt cars with autos in the 10's
#2 I dont have plans to put in a cage like I said Id be happy with a high 11 second car. I dont plan to be a major racer just I just want to be able to go to test and tune once a month or so and have fun.
#3 if It seems Im gonna in many different directions it because Yes Im new to the auto trans in our cars

[mtuggle86]

BTW I was offered a complete built th350 swap as a trade for my m6 this morning from my cousins friend. Its a th350 with a shift kit aftermarket trans cooler a yank 3600 stall and everything else to swap to the auto. I think Im gonna pass because the overdrive issue my cousin was only getting 12mpg with his

[ThreeHonks]

Thats $500 id rather put towards an 80e and have both

sorry but im not interested in banging in my trans tunnel to get one to fit. not to mention a GOOD converter for one can be expensive.

[1BADAIR]

sorry but im not interested in banging in my trans tunnel to get one to fit. not to mention a GOOD converter for one can be expensive.

lol you must not know the tricks

[ThreeHonks]

lol you must not know the tricks

I guess not.

by the way did you go Automatic this year as well? Thats a nice converter in your avatar

[mtuggle86]

Hey guys I got offered this swap a complete TH350 setup im considering it let me know what you guys think of it. My cousin said its legit it his buddys setup. Anybuddy have any idea how to figure out what this would as fare as RPMS on the freeway with 3.73gears? Also what kind of mpg do these get?

Wondering if you would be intrested in trading for a th350 swap. Tranny has 300 miles and has the best of everything billet inner hub hardend 1st and 2nd gear rayban clutches tci manual valve body big pan madman dipstick tube quarter stick shifter tci super street fighter converter 3800 stall electronic speedo conversion kit etc. Let me know if ur intrested it's still in my car can have out this week though thanks anthony