20sickss00

iTrader: (19)

Like it says...just wondering if guys with th400 swaps regret not going with 4l80s? Doing the swap from m6 and don't wan to make wrong choice. I have HCI car with 410s...will be going to 28" tire and possibly 390s if I do th400' if not it'll stay how it is. Do not drive the car often, but just don't want to be winding out the rpms like crazy on the highway or is it not too bad. Any input is appreciated.

cliffdiver86

I'll let you know in a week

GarrettM

iTrader: (6)

I too am looking at doing a th400 swap, one thing I have found through my research is that with any highway time at all you will HATE those 4.10s or 3.90s for that matter. Most guys that are happy with there th400s on the highway run numerically lower gears. If you wont be seeing any highway than it would be different.

I may be wrong here but from my understanding third gear in a 400 is 1:1 on most builds which is basically like staying 4th gear in an M6. That being the case spend a few days running around in 4th and see how you like it. That would probably help make your decision better than anyone else's opinion could.

Camaro9969

iTrader: (12)

Well I've swapped gears a couple times and I'm still not 100% happy. 28" tire with 410s will get annoying if you drive it on the highway but with that tire you prob won't see much street time.
IMO if you have the cash to do a 4l80 dont look back. Its a way better trans than a 400 just more expensive ......

Troy5061

iTrader: (19)

I haven't completely decided yet but I think im going with the th400, I have a 4l80e core but the cost of building it right, getting a nice converter and everything is a lot. The 400 swap is much cheaper, Im FI though so I plan on going with taller 3.54 gears, I would go to 3.23s or 3.08s but I have a dana 60 and they dont offer them. It sucks because Im stuck between the 4l60 and burning up clutch packs every 6 months to a year, bending over and shelling out a ton of cash for an 80e or the 400 and ill lose some creature comforts like od and lockup.
If you dont drive the car often or on the highway much then its a no brainer I would just do the 400.

SuperSlow02

iTrader: (16)

I have a th400/4.10s and it is pretty bad on the highway at 70mph, 55-60 isn't bad though. On long hauls, I trailer my car. Around town is perfectly fine. Exhaust/converter will also be factors

20sickss00

iTrader: (19)

Thanks for the input..yea I think I would be fine with the 3 speed. I hardly drive my car more than 2500 miles a year and long distances it also gets trailored....around town I'm sure I would be fine. The th400 is what I budgeted for, just wanted some input before I gave the order. Going with jakes performance as I have heard nothing other than awesome things about them.

SuperSlow02

iTrader: (16)

I run a 5000 8" from FTI and the street manors are amazing. If highly suggest them for the converter

GMRACER13

iTrader: (1)

I run 3.25:1 rear gears to keep the RPM down on the highway with my TH400. I also changed the gearing in the transmission (2.97 first gear and 1.57 second gear) so it's not a dog out of the hole at the track. With a 28" tire it's not bad at all on the highway. I routinely run 70-75 mph around 3000 RPM.

ramairetransam

iTrader: (18)

gear vendors overdrive unit my friend

therealthatguy

iTrader: (23)

My 400 and 373's make 70 mph at 3800 rpms not highway friendly at all, by still l

los p

iTrader: (2)

i have had it for 2 years now with 3.73s and 28inch tire and 3600tc and its not bad to me and the farthest iv been is about 2hrs out a few times. It takes a little to get use to but it will grow on you compared to endless 4l60 failures!

93camaro_zzz

iTrader: (13)

3rd gear is a 1:1 in all TH400 builds.

Stock vs stock, I would agree with you, but there is a reason that if you look at the top 5 on almost every LS record list, it is either a powerglide or a TH400.

Keep in mind OP, this is on a 26" tire.

Long story short, if you are thinking to swap to TH400, I would like to think that you are swaying your plans more from economy, to performance. Also, lets all keep in mind how much more a 4L80e weighs than a TH400. Which is the main reason all of the fast cars dont run them (Also because they do not need the OD gear).