TH400 questions
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From: Champaign Il
TH400 questions I might have to go with a TH400 in the future, and have some questions: Do they require special convertors, or just standard TH400 convertors? I know I will need a new crossmember, and a shifter, do I just disconnect the wiring and stuff from the 4L60E and tuck it away? Will it fit in the tunnel easily? And my driveshaft must be modified, correct? Will my speedometer and/or odometer still work?
And lastly, I have 3.73 gears and 28" tires, how can I calculate my rpm's for highway driving?
Thanks!
And lastly, I have 3.73 gears and 28" tires, how can I calculate my rpm's for highway driving?
Thanks!
Not sure about the converter. My converter came from yank...not sure if its a special model or not. I know the LS1 converters will not work bc the shaft on the trannys are different! I just disconnected the wiring from the 4l60e and tucked it away with some good ol zip-ties! It fits in the tunnel just fine. The driveshaft is a different length! You will have to get one made. The speedo and odom will not work unless u get some special part of a truck or something.....im not real sure, maybe someone else can elaborate on that one!
As far as rpms....you might as well forget driving anything over 55mph with a loud exhaust. I think Im right around 3000rpms at somewhere around 55. Then again, I have 26'' street tires and 4.11s so you will probably be just fine with 28s and 3.73s.
As far as rpms....you might as well forget driving anything over 55mph with a loud exhaust. I think Im right around 3000rpms at somewhere around 55. Then again, I have 26'' street tires and 4.11s so you will probably be just fine with 28s and 3.73s.
I have a TH350, but the speedo is the same issue either one. You will either need to do the WSS Mod; that is you use a wheel speed sensor, and cross it over to the VSS Signal input and some tuning, but then you wont have ABS. Or you can spend about $150 and get a tailshaft housing from Rossler with the VSS bung Welded in, and a new Reluctor wheel, you pull your TS housing off, pull off the speedo gear, tap on the reluctor wheel and install the new TS Housing, install your VSS Sensor from your old trans and viola, your good to go.
The converter needs to be for a LS1/350 or 400 conversion, or you will need to use a spacer. There are several companies making TC for this, they include:
Yank, Fuddle, TCI, Vigilante, ATI, Continental, NCRC just to name a few of the top ones.
Not sure on 400 DS length, but with the 350 and 9" tailhousing, stock DS is fine, although it could be about 1.25" longer for optimal engagement.
GL
Charlie
The converter needs to be for a LS1/350 or 400 conversion, or you will need to use a spacer. There are several companies making TC for this, they include:
Yank, Fuddle, TCI, Vigilante, ATI, Continental, NCRC just to name a few of the top ones.
Not sure on 400 DS length, but with the 350 and 9" tailhousing, stock DS is fine, although it could be about 1.25" longer for optimal engagement.
GL
Charlie
Teching In
Joined: Aug 2005
Posts: 23
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From: Greenville NC
I run a Turbo 400 in mine.If you go from a 4L60E you need a speed sensor from a 1990 Chevy van with a THM 375 trans,the wiring harness end from the same vehicle and the reluctor ring that goes on the output shaft on the transmission,which you can get all of these from GM.Speedo,cruise,and odometer will work fine.
