Will a Th400 bolt right to a LT1?
You could do a search but yeah it bolts right up....
You'll need a flexplate, converter for a TH400, the TH400 itself (I believe that the one that bolts right up is like a 6" tailshaft version)
You will most likely need a custom driveshaft if swapping from a T56. I've heard that possibly the 4L60 guys can get away with the stocker but not totally sure. I bought a denny's nitrous shaft in custom length. You'll need a new torque arm that doesn't use the tailshaft to bolt the front of the torque arm to since it doesn't have that provision. You'll need a tranny cooler, and a new shifter..... You'll also have to research on a few websites how to make the stock speedo work with the 400... A company called jags that run i believe makes a reluctor gear and a sensor that will convert the mechanical to an electrical impulse that your stock PCM can read...... Look at Jeff Stevens website at http://para.noid.org/~lj for a full writeup on that. I got rid of my speedo recently since i'm running custom gauges and it's primarily a strip car and occasional street terrorist....
if you're thinking about doing it i think it was one of my best mods.... had a t56 and it was a PITA to drive with a big hyd roller cam. choppy, didn't want to pull away without bucking.... high stall converter ate up all the choppiness in the cam. car was much more driveable. just sucked on the highway and gas mileage suffered.... but cutting 1.5 60 foots on motor was effortless....
You'll need a flexplate, converter for a TH400, the TH400 itself (I believe that the one that bolts right up is like a 6" tailshaft version)
You will most likely need a custom driveshaft if swapping from a T56. I've heard that possibly the 4L60 guys can get away with the stocker but not totally sure. I bought a denny's nitrous shaft in custom length. You'll need a new torque arm that doesn't use the tailshaft to bolt the front of the torque arm to since it doesn't have that provision. You'll need a tranny cooler, and a new shifter..... You'll also have to research on a few websites how to make the stock speedo work with the 400... A company called jags that run i believe makes a reluctor gear and a sensor that will convert the mechanical to an electrical impulse that your stock PCM can read...... Look at Jeff Stevens website at http://para.noid.org/~lj for a full writeup on that. I got rid of my speedo recently since i'm running custom gauges and it's primarily a strip car and occasional street terrorist....
if you're thinking about doing it i think it was one of my best mods.... had a t56 and it was a PITA to drive with a big hyd roller cam. choppy, didn't want to pull away without bucking.... high stall converter ate up all the choppiness in the cam. car was much more driveable. just sucked on the highway and gas mileage suffered.... but cutting 1.5 60 foots on motor was effortless....
Last edited by OutlawZ; Aug 2, 2006 at 05:54 PM.
Teching In
Joined: Aug 2006
Posts: 19
Likes: 0
any th400 will bolt up thats what i run. u need a externaly balanced multi bolt pattern flex plate i got mine from prw its a 168 tooth so you will need a starter from a 168 tooth car cause the stock lt1 flywheel is 153.
I used a B&M SFI approved 153 tooth flexplate, LT4 starter, and a Coan 4K stall.
I too have a Denny's shaft and if you install the VSS and reluctor from the early 90s 454 SS pickup then the VSS pigtail will plug right in. Rossler installed one in the TH400 I have and it was plug and play and the speedo works fine.
I agree that if its not your daily driver then the TH400 will be the best mod you have ever done.
I love mine.
I too have a Denny's shaft and if you install the VSS and reluctor from the early 90s 454 SS pickup then the VSS pigtail will plug right in. Rossler installed one in the TH400 I have and it was plug and play and the speedo works fine.
I agree that if its not your daily driver then the TH400 will be the best mod you have ever done.
I love mine.
Thread Starter
Launching!
Joined: Feb 2004
Posts: 228
Likes: 2
From: Lakeland, Fl.
Originally Posted by OutlawZ
No a 4L60 torque converter AFAIK will NOT fit a TH400.... it needs a TH400 converter...
Okay, thanks alot. It is going to be my daily driver, I don't mind though, I'm sure it will get better mileage and performance than an old school sbc.
