Need opinions and facts.

[Durney]

Well it seems this wont be as easy as i thought. The new 67 4x4 project has hit an impass. I was going to swap the transfer for a NP205 but now a customer we build engines for has donated a like new (4000 mile) 4L80E trans and now that becomes an option.

Heres the questions - I can get the laptop controller for the 4L80E from TCI for about 600.00 (mail order is 760) but I can also just buy a new 700R4 for about the same money. I would like to use the strongest(4L80E/205) and EASIEST to swap(700R4/?) combo possible....... your thoughts?

Also I am thinking that either way I may end up having to use a one piece driveshaft?

Thanks in advance guys.

(sure wish the search was working....)

[ljbear]

The newer overdrives are nice, but depending on how you do it they can get pricey. Consider that the older trucks front drive is off of the right side of the vehicle and the newer are off of the left. With that said you are probably going to have to mix an old transfer case with new transmission, so an adapter is probably in your future. Advance Adapterhas an adapter for almost any application. You'll need to find out what the output shaft and input shaft differences are on the two. I went through this when I swapped out a 4 speed for a 5 speed and it seemed like there was always another part or cost just around the corner. Give Advance a call and run it by them, they'll tell you what you'll need to make it work. Good Luck

LJ

[Richard]

I have seen your previous posts on this subject and I am installing a 4L80E in my 72, here is the info and the parts I have. You need a TH400 adapter which are being reproduced now. The index ring that keys into the back of the tranny needs to be milled to a smaller diameter and it will bolt right to the 4L80E. The output shaft for the tranney needs a 4 1/2" stickout. the easiest way to accomplish this is to us the output shaft that comes in the motorhome version of the tranney. It is fully splined and can be cut down to the proper lenght. You can change the input gear on your TH350/205 transfer case to the female input TH400 type, easy swap. This setup will move the transfer case back about 5". I believe this is stronger as the splined coupler sleeve is eliminated.
If you want to use the 700R4 it will bolt directly to the TH350/NP205 adapter. The proper output shaft just needs to be installed in the 700R4 available from advance adapters or 4wheel heaven. If I recall the transfer case is moved back only about a 1/2" The stock auto linkage should work fine in both situations as the distance from the bellhousing to the shift location is the same in all GM auto tranneys. I was told the steering column needs to be slightly modified to allow the shifter to go all the way into first. Some filing is involved is all I know, my tilt column was done when it was rebuilt.
Drive shaft work is relativly inexpensive if you are just having them retubed (lenghtened) or shortened and rebalanced. So dont fret about the shafts the bonuses of the new overdrive will offset any vosts IMHO. Hope this helps some.

[Durney]

Outstanding info Richard and good luck with the swap. I am leaning toward the 700R4 because this one won't see much abuse and the install may be cleaner that way. I had another customer drop off a 700 case today and I did some mock ups for a shifter Idea. I think i am going to use the Lokar trans mounted street rod shifter but fab my own handle on it so that it looks like the original SM420 shifter and it also looks like I wont have to change the tunnel much (if at all except the transfer shifter).

The question then becomes what transfer should I use?

The 205 for brute strength? OR what ever was used on the 700 (208?241?) and hope it fits without too much hassle.

[Mikeflyer]

I have just about finished my install of a 700r4 in my 72 with a NP205, just hooking up throttle linkage and TV cable. I elected to move the engine forward approx 1 3/4 inches.
This allowed me to keep the same transfer case location eliminating any shifter relocation problems and no driveshaft work. I am running electric fans and still have lots of room between engine and radiator. I already had a Kugel Componets shift linkage which works great. If you are running stock linkage you will have to make some mods as the shift lever moves forward in relation to the position of the T350 shifter shaft.
If I can provide any additional information just let me know.

[Durney]

Thanks Mike,

I thought about moving the engine forward also but it looks like all i will need to do is shorten the first drive shaft about an inch (if at all). I am definitely going the 700/205 route and have most of the items now.

What I do need is a good output shaft, bearing retainer and yoke to convert the slip yoke (long/ odd) output to a fixed yoke (short /common) configuration. I can aslo use a nicer coupler between the 700(th350) and NP205 as the one I have is rough.

Where does your np shift lever enter your high hump Mike? Got any photos?

thanks !

[Mikeflyer]

Durney

My transfer case shift lever is in the stock location. This is due to moving the engine forward instead of moving the transmission/transfercase crossmember back.

I wish I could help you on the parts but do not have any additional.

I also am away from home and cannot take pics at this time. When I return I will send if you still want, but there going to look just like original and don't think they would do you any good.

Mike

[Durney]

I guess that was a dumb question as your origianlly had the 2305 right? Well I am replacing the T221 so my t-case lever is up and slightly right of the shifter hole and I think the 205 will be low left.