700r4 or th400

[munroe]

im gettin ready to put the new tbi 350 in my 87. before i do i need to choose the tranny, stay with the th400 thats in it or switch to the 700r4 i can get for a song. the truck will do a fair ammount of highway cruisin, but its also going to see the drag strip some. what do you guys think, leave it as is or spend some money on shift kits and servos and put the 700 in

[gchemist]

I have a stout 700R4 with upgrades. Worth every penny.

700R4!

[MylilBowTie]

How about this use the 700r4 but keep the th400. Is the truck a long wheel base or short? Drive shaft one piece or two? What is the load capacity?

[munroe]

well, the deal is i can trade the carbed 350 i have for the 700, all the u joints and a one peice luminum driveshaft. then i could sell the 400 and put the 300 or so into the truck. the truck is a long wheel base 87 2 wheel drive

[N2TRUX]

You have to make that decision based on your actual needs. If the majority of your use will be commuting, then the OD in the 700 is clearly an advantage. If your just going to use it for cruisin, and trips to the drags then the 400 will last longer.

[Prerunner1982]

If you get the 700 built up then it should be just fine. The OD would be great for cruisin down the highway and the lower first gear would be good for intown commuting and quick off the line (compared to a th350 or 400).

My 87 had the 700r4 and go about 16mpg, which I didnt think was too bad for a fullsized truck of that age as my wifes s-10 4x4 4door blazer only gets 16.5mpg.

[munroe]

im going to be usin the truck for my daily driver from around may on till september, makin a 10 or so km round trip to the base everyday, plus weekend trips and all the runnin around ill do. the 700s od might be the way to go

[454HO]

What rear end gears do you have now? I would not recommend the 700R4 unless you had at least 3.08 rear gears.... 3.42 would be better and 3.73 would be ideal.

[bigblock73]

I agree with Greg.

If the gears are low enough...700 for sure.

[N2TRUX]

Yeah, your right. I didn't think about it being an 87 and could have 2.56 or whatever those insanely high gears were.

[MylilBowTie]

Just my opinion but I would keep the th400. I doesn't seem like a good deal to me trading a 350 for a 700r4 trans. Then needing to upgrade the 700r4 parts. True you wont have overdrive but its not the end of the world. TBI engines are pretty good on gas and it is a truck.

Im getting right about 13 mpg with a 234,000 mile 305 4bbl - th350 - 3.42 gears.

[82c10]

i've seen turbo 400's built and blow up, and i've seen built 700r-4's blow up with a lot less power

[MylilBowTie]

The th400 is way stronger than the 700r4 is stock or built. Cost is also much less. I dont really think its an even comparison.

[munroe]

looks like most are pullin for the 400

[Duro5341]

Like others have said.....it all depends on what your plans are for the truck...

Money aside.....what are your plans for the truck

If your gunna drag race, sunday cruiser, or pull a a decent size trailer I would stick with the Th400..for it's durability

If it's a DD, and you don't pull or haul anything....just back and forth to work, and groceries...then go with the 700R4

Just my 2 cents
Duro

[munroe]

its gonna be a combo of both. drivnin to work in the spring and summer with the occasional weekend trip and drag run

[edflores]

the 700 is better due to the gearing. i like having overdrive and that low first. and i get about 20 mpg. my truck is way faster than any older truck i had with a 350/350 combo. how many horse you have under the hood?

[Duro5341]

Originally Posted by munroe

its gonna be a combo of both. drivnin to work in the spring and summer with the occasional weekend trip and drag run

Well the Drag runs will absolutly anilate the 700R4....I'd say suck it up, and pay for the extra Gas....go for the TH400. Lets face it gas is cheaper than rebuilding the 700R4 when it breaks

Duro

[streetstar]

if your rt commute is only 10km (little over 6 miles to you non-metric guys)

then your wallet is not going to hurt too much just keeping the th 400. The 400 laughs at loads that would grenade most 700's.
But then again - the 400 is overkill for a lot of small blocks, and if yours is TBI, its probably gonna have a 275-325 hp output gross, if that. The 400 will cost you more power output at the rear wheels than the 700 -- which is more than worth it if you have a 550hp big bock, but with a 300 horse 350, you dont have a lot to spare

I'd say its a push, either way

[MylilBowTie]

I don't think a th400 is over kill for a small block v8. I've seen 4.3 mated to th400s stock. If you decided to use the 700r4 get a Transgo shift kit. Its way better than the rest and will let it live a little longer. Transmission coolers and remote oil filters help a lot also. That goes for either transmission.