White.Lightning

iTrader: (53)

Hey guys. Long story short- stock bottom, heads/cam car LS1 based. T56 car originally, want to switch to an auto. I haven't been able to get a clear answer on which transmission I should go with an why. If you vote, drop a message saying why you chose that specific transmission for my setup.

Goal is eventually going to be a "9 second street car", LS3 based, FI or N20. I have a company truck I drive during the week. The T/A is my primary car otherwise and see's city and highway driving on the weekends. Car is full weight now, and will probably never be too much lighter considering a 6pt cage, etc will be added to offset any weight reduction.

Any questions ask. Choices are TH350, TH400, Powerglide, 4L60e, 4L80e. My car is a 1998 car, so if I went with 4L80e, I would have to swap to a 99+ PCM and what not. Still researching what needs to be done with that.

Thanks for looking,
Andy

EDS01SS

iTrader: (30)

well if it will be driven on the street and highway then the 4L80E is clearly your best choice if you want to keep an overdrive and still have a good gear in the rearend and still run the times that you want.

White.Lightning

iTrader: (53)

It will be driven on the highway until I get another vehicle (beater)

kinglt-1

iTrader: (26)

I think a built 4l60e can handle your goal for 9's, prolly not much more than that tho!

twitchtwice

iTrader: (12)

i say get the 4l80 because its stronger then the 4l60 and has an overdrive unlike the th350-400

z28boy

iTrader: (2)

4l80 all the way, people on here have been rocking the junkyard built ones including myself

calongo_SS

iTrader: (7)

If it's going to be a 9 sec street car you will get tired of no OD with a 400, and will get tired of breaking 60's. Just get an 80 right from the start.

White.Lightning

iTrader: (53)

I'm thinking a manual valve body might be the best option for me. It's basically a TH400 with overdrive, and I wouldn't have to swap PCM's/harnesses/etc.

TXCAMSS

iTrader: (60)

Yeah I agree. The PCM harness swap will be a pain and not worth it IMO. I'd go with a 4L80E with a MVB and you'll be covered. We had great luck with our built 4L60E, but we were already set up for it with the 01 PCM. Since you have to do a conversion anyway, you may as well cover yourself with a 4L80E and manually shift it. If you are going to see freeway driving, an OD is a must.

Circle D or FLT can build you one that you'll never have to worry about.

G/L

White.Lightning

iTrader: (53)

I already have a builder in line

I was going to contact Circle D to see what they could do for a converter. It's between them and Coan.

TXCAMSS

iTrader: (60)

The 4L series converters are Circle Ds specialty and I believe they offer one free restall to LS1tech members. That's a no-brainer especially since the cars final HP hasn't been confirmed yet. It seems we always want a little more stall.lol.

G/L and keep us updated on the build.