14 replies to this topic

[dattoman]

Go the T350 unless you want highway cruising and running 3.7 or lower gears

T400 robs more power

No tunnel mods required for any of them usually

[ls2lxhatch]

The TH700R4 give you the option to setup the car with a 3.55 - 4.11 diff for the 1/4 mile and still be able to cruise at highway speed.

TH700R4
1st - 3.06
2nd - 1.63
3rd - 1.0
4th - 0.7

TH350
1st - 2.52
2nd - 1.52
3rd - 1.0

The GearCalc program will help to to work out what rpm/speed you will be doing for a given tyre, diff and gearbox. Download the GearCalc program, plug in the tyre, gearbox and diff ratios and have a play. There appears to be a problem with the tyre calc in the program so enter the diameter from the Toyo Proxes
chart.

You can buy a TH700 4L65e brand new for under $2000. This is the current GM auto, it will require significant transmission tunnel mods and a computer but will handle the power out of the box.

The early cable kickdown TH700R4 4L60 and the electronic TH700R4 4L60e are the easiest to fit.

Edited by ls2lxhatch, 15 February 2008 - 09:38 PM.

[yel327]

In an LH-UC use the TH350. You'll have to beef it up for that sort of hp though, as standard a TH350 isn't much different in strength to a late model trimatic. A TH400 is a much better gearbox, but I seriously doubt one would fit in an LH-UC tunnel properly without tunnel mods (but will stand corrected if someone has done it!). Forget the TH700R4 unless you really want overdrive as they are not real strong (unless beefed up heaps) and cost a lot more to build. The TH350 should bolt straight in, use a 4spd or trimatic tailshaft and a UC shifter. But you'll have to get a crossmember made and buy a speedo cable to suit a Saginaw or TH350 into Torana.

[LS1LX]

You will get bored of the powerglide after 10 minutes on the street, unless you have 4.56's and 500HP. There a boring gearbox on the street.

The Turbo 700 is a waste of time, you can spend $5k on it and it still won't be as strong as a standard 30 year old TH400. Who really takes a torana with flash paintwork on the highway to cop stone chips? Besides the Pacific hwy on the way to Toranafest I don't think you'd see too many Torana's cruising the highway any time soon.

TH350 is what I run, I like them, it will fit and handle the power after a good build up, wont rob as much HP as a TH400 but its no where near as strong as a TH400.

If you want to "set n forget", get yourself a TH400 put a $100 kit thru it and it will handle 500HP in stock form and you will never have a problem. It will suck another 10hp over the TH350 but you dont need to spend any money to strengthen it, its got the shear size, larger input/output shafts etc.

You will need to mod the floor a little bit for the TH400, I have yet to see a TH400 in an LH/X without having at least 1 little love tap.

I would be choosing between a TH350 or 400, wouldnt look twice at the other 2 options for a tough streeter.