700R4 and 208 in my '69

[Purs]

OK, been reading all that I can find here and seems like everyone thinks that a TH350 and NP205 are the way to go for 1st Gen Blazers (if you want an automatic). However, I was talking to a 67-72 truck guy here and he says if I'm not going to be racing or wheelin' very hard then there's nothing wrong with the 700R4 and NP208 setup.... This rig will see off road action occasionally but it won't be a mud buggy, rock crawling, or anything else extreme.

I'd like to get you experienced guys opinions on this before I go that direction. I already have the front and rear driveshafts for this setup but no crossmember. If I do this, do I need a later model crossmember or my 67-72 crossmember?

I've got a boardmember who has made me a very generous offer of his TH350/NP205 setup but he is a million miles away (almost!) but I'm afraid shipping is going to make this not very cost effective.

thanks for helping me move forward in getting my '69 K5 roadworthy.

[msgross]

This website says it all... NP 205, gear driven = bulletproof

http://www.high-impact.net/transmiss...case_NP205.htm

NP 208 = chain driven

http://www.high-impact.net/transmiss...case_np208.htm


I'd try to find a 205 with an auto hooked up to it. my 2 cents...

[1969k10stepside]

The th350/205 combo is a good combo except for the notorious leaking of tranny fluid into the t-case..The only way to up the strength would be a turbo 400/np205 combo....I vote th350/np205 but use what you can and maybe eventually you will find a np205 to use and atleast your blazer will move now..Finding a np205 for a auto will be kinda tricky...Only used in 70-72 trucks/burbs and 69-72 Blazers/Jimmys...then some in later years,but them are kinda hard to find too

[Purs]

thanks for the links. I'm learning more every minute.

[Tink]

By occasional wheel - you mean some light trails? Honestly, I had a friend with a 700R4/208 set-up, who wheeled the crap out of it and the only thing he ever broke was U-joints. I'm gonna go against the grain here - for light wheeling, a 700R4/208 should be fine... and a 700R4 will be much better than the TH350 if you plan to drive it on road/interstate a lot, IMO. I 'lightly' wheel a high mileage S10 Blazer with a 700R4/231 and have never had any problems with it - I also use it as a daily driver and that 700R4 is a blessing on the interstate since I'm running 4.11s.

[bdozeraz]

If you don't plan on beating on it or running huge tires the 700r4/208 combo should be fine. The 205 is definately stronger and can still be adapted to fit the 700r4 but the 208 has a lower gear ratio in 4lo so that is a plus.

[swamphunter]

I have a 69 that is leaking trans fluid into the transfer case! I did not realize that this was a common problem. Is there a fix other than just replacing the seal on the transmission?
Swamp

[brianthelion02]

I put a 700r with a 241 tcase in my truck,sure a lot better than the sm-465 and rockwell,that thing sounded like a jet airplane before!!!!!I should say that i am using my truck more for towing than anything else!!!!!!It will see very little real off road stuff!!!!!!!And it does 75 mph n/p,even with the stock 4.56 gears!!!!!!Gets about 14 mph too,was gettin 8 mph before!!!!!!

[bdozeraz]

Originally Posted by swamphunter

I have a 69 that is leaking trans fluid into the transfer case! I did not realize that this was a common problem. Is there a fix other than just replacing the seal on the transmission?
Swamp

There are two seals in the adapter between the transmission and transfercase. There is also an O'ring on I believe the splined input shaft of the transfer case, I don't remember now for sure. I know there is one there somewhere that also needs to be replaced. I replaced just the seals on mine and it kept leaking and when I took it apart the second time I found the O'ring and that fixed it.

[Zoomad75]

Light wheeling, the 700/208 combo is just fine. Strengthwise between a th350 and 700r4 are debatable. the th350 is probably stronger out of the box, but lacks od. The 700r4 can be built to overcome the known issues on it and be just as strong as a th350. Plus side is besides having OD, the 700 has a deeper 1st gear ratio than the th350.

On the t-case side, nothing is stronger than a 205 but it's main downfall is the puny 2:1 low range. The 208 is pretty strong as aluminium chain driven cases go and it does have a better low range ratio. If not wheeled on like a pro rock crawler or running mudbogs door handle deep both should hold up fine.

[ccpanel]

so for snow-driven paved roads 3-5 times/year for 20-50 miles/time to get over sierras i would be fine with 700/208 or 700/231?

29" street tires in a 4200# 1950 suburban with 4BT cummins.

which transfer should i find? and do they come in driver or apss drop or both?

this will be driven on paved roads only in snowy/icy conditions. also i must be able to shift on the fly with manual locking hubs.

[cstanley]

Originally Posted by bdozeraz

If you don't plan on beating on it or running huge tires the 700r4/208 combo should be fine. The 205 is definately stronger and can still be adapted to fit the 700r4 but the 208 has a lower gear ratio in 4lo so that is a plus.

can you define "huge tires?" are 33"s huge?

[68K20 x Drill]

IMO a 208 should be fine as long as you don't have better traction than a stock truck.
The fuel savings from a 700 R will easily buy as many replacement NP208's as you could ever need.
Get the newest 700 you can, they made a good few improvements over the years.
Be sure the TV cable is adjusted properly, or your new tranny dies.

[ccpanel]

thanks! i want the newest 700 i can get withOUT a computer(wifes demand) its gotta have gear drive speedo and no computer hookup.

followup que-if i get setup of 350/208-can i find 700 and just swap the 350 out(before installation) since they are same spline?
thanks

[68K20 x Drill]

not sure about the tcase, but the electric sensors use the same gear as a speedo, so no problem there.

[duallyjams]

I had a 84 4x4 with a sm465 np208 that used in truck pulling for three years and never had a problem with the np208.I broke two clutches,rear end yoke.front axle,but never had a problem with the transfer case,and the motor was a 400 smblk went 10.50 in a car.
I have a spare 700r and 208 in a 86

[earl87gta]

If you have a 350 /205 set up why would you do all of that for the over drive just get the $150 tale shaft from advanced adaptors have it put in to the 700r4 you are going to use and have the best of both worlds. you can probly sell the 350 trans for enough to pay for the adaptor then your only out the cost of the 700r4. Thats what I would do.

[dpatrickunc]

I am also exploring the Idea of installing a 700R4...currently running a TH 350 and NP 205. I would like to have OD. I run a TH 350 and 208 in my mud bog truck and it has worked very well, I have had a few failures but usually due to a borken front shaft. The 205 has a 1.98to1 lo range and the 208 has a 2.52 to 1 Lo range. Painless wiring offeres a kit to control the lock up and OD for about $150.00 so you get the OD and the lock up. I am definately leaning towards the 700R4

[72 CustomCamper]

I had a friend that ran a 700/208 combo in his 84 truck with 40 inch Ground Hawgs and never had a problem. The truck was a daily driver plus a weekend beater...


Chuck