blown transmission - what are my options ?

[koolray09]

I purchased a 1978 GMC Sierra 1/2 Shortbed 4x4 with a bad turbo 350 transmission 27 spline - metal frags in bottom of transmission - transmission won't go into any gear - transmission rolls in any gear.  The engine is a chevy 350.

I can get the transmission rebuilt -  I am open to going with a different transmission/transfer case setup - I would like to keep modifications to a minimum.  I won't be doing a LOT of offroading, probably almost none.

I have access to a turbo 350 transmission 32 spline with "K" marking with an NP208 ( it may be a 205 )  The driveshafts I have will not marry with this case.  Does the transmission cross member have to be changed - what about where the 4x4 L/H selector pokes up through the floor ?  I know that one end of my DS is splined and I can pull it off - is it possible to replace the spline end with a yoke that marries up to the 205 / 208.  ( I've got a call in to find out if it is a 205 or a 208 ).

Like I said, i won't be doing a lot of off roading. I want to marry a drive train to my engine that has a solid history of performance.

if folks can let me know what replacements they used, on and what modifications/replacements/after market parts they needed, would be helpful.  thanks to all

[VileZambonie]

700R4/4L60

[Irish_Alley]

heres the break down on what spline counts were on what trans

th400 and 4l80e are a 32 spline

700r4, 4l60 and th350 are 27 splines

sm465 from 68-78 is 10 splines (35 for 2wd)
79+ is 32 splines (35 for 2wd).

if you have a th350 with 32 splines somethings wrong with that info

[philo_beddoe]

I would get the 350 rebuilt or get a brand new th400.  Powerglides are nice too.

[koolray09]

I found a "K" style transmission with bad pump. The pump from my th350 is good.  Transmission guy is gonna rebuild the "K" style th350 transmission and frankenstein a good transmission with rebuild kit.
thanks for all your input.

After transmission/xfer case installation and proof vehicle drives, I know it runs...I will then work on getting it to stop.  new master cylinder and brakes.  Then radiator/water pump.   Then fuel system overhaul.
Maybe not in that order, but those things need to be done. oh yes. front bumper install and front fender replacements. Then i'll be done.   My family does not understand me.

[koolray09]

Transmission is rebuilt.

Transmission is happily married to NP203...now just need them volunteers to show up at my house to help with reinstallation... 

You only need to know how to work on 1/2 your car, cause everywhere I read - Installation is opposite of deinstallation.

[hatzie]

The "K" transmission is a lighter duty TH400 made for automobiles. 
Two TH400 cases were available. 4x4 models have the "HD" case (stamped on the housing) with a cast-aluminum flywheel cover. Car applications got the "K"-stamped case and a plastic or sheet-steel cover.

[philo_beddoe]

I found a "K" style transmission with bad pump. The pump from my th350 is good.  Transmission guy is gonna rebuild the "K" style th350 transmission and frankenstein a good transmission with rebuild kit.
thanks for all your input.

After transmission/xfer case installation and proof vehicle drives, I know it runs...I will then work on getting it to stop.  new master cylinder and brakes.  Then radiator/water pump.   Then fuel system overhaul.
Maybe not in that order, but those things need to be done. oh yes. front bumper install and front fender replacements. Then i'll be done.   My family does not understand me.

I know how ya feel koolray, i just did a non-frame off resto, now it just needs some nice paint. Been going at it since march, part after part after part, some oem, some junkyard, some aftermkt. Its nice when you see a little light at the end of a long dark expensive tunnel. And no, nobody except the folks on this forum will understand.