TH350 vs TH400 / speedo
04-08-2009, 05:57 PM
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TH350 vs TH400 / speedo Over the past three months I have searched through every last sticky/website/vendor for information on converting an f-body to a TH400/350 and here are the questions that I have after i exhausted my poor retinas staring at the computer screen
So I was dead set on a turbo400 swap in my '99 SS after frying about four Stage-2 4L60s but I have some friends who own/operate a shop in my town and when I talked to him, he convinced me to go TH350. It's lighter and has less parasitic loss (40 horses less than a TH400!) plus that fact that it works with the stock driveshaft because its the longer 9". The one he is selling me is identical to the one he uses in his 8 second all-motor Chevelle and if it stands up to his wheelstands, it'll take my little 10 second runs
Any objections to a TH350 over a TH400? Crossmembers are just as easy to find (thanks to Dave at Yank!!) and converters for both are like ricers, they're everywhere! Experiences with either? Suggestions?
Now about the speedo:
I found a site that has the VSS and the rotor (plus they are GM parts, but they're way cheaper online then at my dealer) for a TH400 but will the rotor and the VSS for the 400 fit 350?
Do I have to get a different tailshaft?
Will the VSS off of my 4L60 fit and I just need the new ring?
Can I rip the ring off the 4L60 and press it onto the TH350 AND use the VSS from it?
Or am I stuck buying the parts? And if so...Which VSS part# and rotor part# would work with the TH350?
I read about splicing the ABS wires into the VSS but I don't have a tuner, nor does anybody around me and the nearest person wants to charge 400 dollars to do it and sending it off to get a mail-order tune would take months unless they got it dead on the first try, which i doubt. Any other way of doing it without a tuner and calibrating gears and such?
Thanks a million!
So I was dead set on a turbo400 swap in my '99 SS after frying about four Stage-2 4L60s but I have some friends who own/operate a shop in my town and when I talked to him, he convinced me to go TH350. It's lighter and has less parasitic loss (40 horses less than a TH400!) plus that fact that it works with the stock driveshaft because its the longer 9". The one he is selling me is identical to the one he uses in his 8 second all-motor Chevelle and if it stands up to his wheelstands, it'll take my little 10 second runs
Any objections to a TH350 over a TH400? Crossmembers are just as easy to find (thanks to Dave at Yank!!) and converters for both are like ricers, they're everywhere! Experiences with either? Suggestions?Now about the speedo:
I found a site that has the VSS and the rotor (plus they are GM parts, but they're way cheaper online then at my dealer) for a TH400 but will the rotor and the VSS for the 400 fit 350?
Do I have to get a different tailshaft?
Will the VSS off of my 4L60 fit and I just need the new ring?
Can I rip the ring off the 4L60 and press it onto the TH350 AND use the VSS from it?
Or am I stuck buying the parts? And if so...Which VSS part# and rotor part# would work with the TH350?
I read about splicing the ABS wires into the VSS but I don't have a tuner, nor does anybody around me and the nearest person wants to charge 400 dollars to do it and sending it off to get a mail-order tune would take months unless they got it dead on the first try, which i doubt. Any other way of doing it without a tuner and calibrating gears and such?
Thanks a million!
04-08-2009, 07:33 PM
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Someone makes a tailshaft with the parts already installed. I don't remember who it is though. You can use the tach to figure out MPH based on RPM, this is what I do.
04-08-2009, 08:24 PM
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If you were to play eenie-meenie-miney-mo with the companies that you THINK make that part...Who would they be?
That's what I was going to do, also. Especially since I won't be using cruise control or the odo anymore...But does it affect any aspect of the PCMs control of the motor? Such as lean/rich?
That's what I was going to do, also. Especially since I won't be using cruise control or the odo anymore...But does it affect any aspect of the PCMs control of the motor? Such as lean/rich?
04-08-2009, 08:35 PM
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