Chiropaul

iTrader: (2)

I have a TH400 that I've beat on for a while in my LSx swap 67 Tempest, it is a unit I got for about $150 and its on its last legs. I bought a built TH400 with reverse manual valve body and trans brake from my neighbor who races an 8 second nova. This transmission is good for about 900+hp and I got it for $1k.

My plan was to put it in my Tempest, but I daily drive my beast to work and like to jump on the freeway for about 4-5 miles to shorten my drive. I'm usually churning about 3300-3500rpm on the freeway with the TH400 and the 3.73s out back. The car is bulletproof reliable other than the tranny, and I'd like to drive it on longer (1-2hr) drives and so I thought I would get a 4L80e in there and found some higher mileage units on car-part.com near my house for $800.

Only downside is I need a new torque converter, and probably a new driveshaft for the new tranny, plus my motor is putting out about 500hp and I want to put a 150 shot on it soon too. So I am going back an forth on selling my built TH400 that is sitting in my garage and getting the 4l80 and all the goodies to go with it, or just popping the TH400 in and dealing with high RPM cruising.

What should I do???!!!

1CAMWNDR

iTrader: (21)

Taller rear tires for the street.....probably not much difference in rpm.
Or get the 4L80E Stage 2 or 3 from Jakes Performance. I would personally NOT talk you out of the 4L80E

Chiropaul

iTrader: (2)

I kind of figured I'd end up going for the 4L80E, just needed a little persuasion to make the leap.

cuslog

3300 on the freeway W/ TH400 will drop to 2475 W/ 4L80
and it's just as strong if not stronger than the 400 - you'll love it.

Mike Morris

iTrader: (55)

Do the swap!!!

Mystery Bird

iTrader: (7)

Go with the 80, you wont regret it.

Chiropaul

iTrader: (2)

My wife probably hates LS1tech by now!!!! But it is a done deal. Time to get the shift kit and torque converter ordered up and probably an SFI flywheel while i'm at it.

high impact

iTrader: (5)

If you wanna cruise the 80 is the way to go...keep the 400 if you plan to drag race at the track all the time. Sounds like you WANT an overdrive. Go for it!