[Tom Ziokowski]

i have an 87 that i was thinking about dropping a LS-1 or a zz4 crate in it. i have a 700r4 trans and i want to know what i need to do so that it will handle the power of the new engine and not loose a lot of horsepower in the trans. also what kind of stall should i use for the horsepower (350-400hp) of these two engines has anyone done this? any idea of the cost?
thanks

[Shawn]

Tom, I would not worry about power loss in the tranny, the difference is minimal. A beefy TH400 only uses about 8 more horses than a weakling 700R4 transmission, and in the grand scheme of things, like a 400 HP engine, this is miniscule. Ultimate in reliability - Go for A TH400, they're hard to break. But... you can buy a 700R4 that will survive behind 400+ HP, but you'll pay for it. TCI, B&M and some others offer beefed up 700R4's, but plan on spending about $1400-1800 for one as opposed to less than half that for a bullet proof TH400. If money is no object, you can dump enough cash into a 700R4 to make it survive.

It's even difficult to have a kit built into a 700R4 for less than what a new TCI or B&M sells for, and believe me, there aren't many places that want to build a high performance kit into a 700R4 because it's a nightmare. The ONLY reason to get a 700R4 is for the OD, and if you can live without it, then go for the TH400. As for the torque converter, it really depends on the engines torque at a given RPM and weight of the car. It's not a very simple answer, but if you go to TCI's web site they've got some good guidelines on which converter is right. The engines you are referring to probably would want something like a 1000 RPM over stock.

------------------
Shawn "My Camaro is a money pit" Peterson

[second2nd]

This months CHP mag, pg. 28, has a decent article on OD and specs for various trannys. Shawn is correct, the beefed up 700r4's are very pricey.

[TwoFast4Lv]

I guess 10sec. 700s suck?

the big adavtange to the 700 is the 3.08 1st gear and coresponing 2nd gear. O/D is very nice also

------------------
Thump'n hard 'n Fly'n Low...2FST4LV

[Shawn]

I've read through this a few times and can't quite find where it says that a TH700 sucks. It does however mention that it is very pricey to make them last. I would wager to say that a 10 sec 700R4 isn't stock... At least not for more than 3 runs down the strip.

1969 Z28

[This message has been edited by Shawn (edited 12-02-99).]

[JimM]

700R4's suck? Weakling? Guys, this is the trans GM uses in all V8 powered things, including Vette's and other LS1's, and all automatic trans trucks. They do not suck nor are they weak. Stock ones will handle 450 Ft Lbs of torque forever is kept cool and not abused. They are expensive, though. As food for thought, my vette w/ 3.23 gear has the same first gear ratio as a t400 with 4.88's, but I only spin 1700 rpm on the highway at eighty!

[josh_sallee]

i would say the 700 is a very respectable tranie. the TH400 is way to much trans. for that engine, if you wanted to go to three speed i would suggest the TH350. i think the 400 would rob too much horspower vs. the integrity of the 400. as for stall, it would depend on how radical of cam you want to use. i say at least 1000 over stock for starters.

josh

[MarkM]

I think 700 got a bad rep at first because prople were using the earlier ones that are'nt as strong. Art Carr can build one and they claim it will handle over 900 hp and 725 ft lb. Don't knock the 700 till you've tried one. Yes for a drag only or radicle motor go with a 400, but once you get an overdrive you'll never want to go back. I have one in my 68 468 BB and it works great.

[YenkoYS100]

Is there something wrong with a 4L80E ? I'd hate to price that 700R4 that will handle the 900hp and 725ft.lbs. of torque. I think it's great that most modified 700R4's advertised wont handle the torque of a stock 1970 454 LS5 (500ft.lbs.).Think about it? A wimpy small block with a small dose of Nitrous will explode a modified 700R4.!! I heard from a GM Engineer that the 700R4 saved many tranny shops from going belly up!! The shops wrote GM many letters of thanks. Rick
'68 Camaro SS 427 N2O 4 Speed BW ST-10
'66 Yenko Stinger #YS-100 4speed 220+hp 164c.i. 2050lbs.

[MarkM]

The art carr 700r4 sells for around $1800, less converter which is still less then half of what I've seen a 4L80E advirtised for. I know I guy with a 70 Nova that runs a 700, its a 434 sb with nitrous and it runs low 9's.

------------------
68 468 700R4