Cascade Crew

fiveoformula · Posted: Sun Aug 02, 2009 6:38 pm Post subject: Tranny swapage questions

So my girlfriend drives a '72 3/4 chev pickup. She and I and her dad want to take out the leaky T350 and put in a good 700R4 so she can have the overdrive on the highway back and fortth from school, And since he has one laying around from his project truck...

I know we will have to add a TV cable, and figure out something for the torque converter lock-up, but is this a bolt in swap? I can't remember if the two trans are the same length or not... Will we need a drive shaft?
Help is greatly appreciated as always guys.

90droptoproc · Posted: Sun Aug 02, 2009 7:30 pm Post subject:

need to get your drive shaft shortened, and may need a different cross member, although sometimes your stock one can be reused by bolting it into a different set of holes in the frame

chevymad · Posted: Sun Aug 02, 2009 8:24 pm Post subject:

Ya, you'll need to shorten the driveshaft and move the crossmember. Not sure where the crossmember will end up, but the frames are open on these trucks, so you can just drill holes. Make sure you get the tv set up exactly right, theres several sites that will show you exactly how to do it, or you can buy bowtie overdrives tv made easy kit. The kickdown on the old quadrajets is not in the right place for the newer tv cable.

Several ways you can do the lockup. On my 70 I bought the vacuum switch, delay valve, and cruise brake switch. This is how chevy did it on their early 80s vans with od. You can also buy a controller from b&m or tci.

I put a 200 4r in my 70. Its exactly the same length as a th350, so it required no driveshaft mods. But I still had to hook up the lockup and bought the tv made eazy kit for a holley. I tried holleys brackets and they did not work.

Your column shifter will work fine, the gears just won't read right.

fiveoformula · Posted: Mon Aug 03, 2009 8:16 pm Post subject:

Alright thats pretty much what I needed to know, her dad is still convinced that he won't need to shorten the drive shaft. He is very stubburn. Rolling Eyes

Like his daughter... But it's looking like im gonna look real smart once we pull the trans. haha Very Happy

Twilightoptics · Posted: Mon Aug 03, 2009 8:40 pm Post subject:

Only way he wont need to shorten the driveline is if it has the longer style 9" tail.

When I put a TH350 in my Camaro I had it built with the longer tail/mainshaft so I wouldn't have to lengthen the driveline.

chevymad · Posted: Mon Aug 03, 2009 8:45 pm Post subject:

If its the stock 72 trans is should be the short one in a pickup. 73 up they used the long ones. It's probably not the stock trans though with a th350 in a 3/4 ton. I thought the 3/4s all got th400s until 73.

fiveoformula · Posted: Mon Aug 03, 2009 9:53 pm Post subject:

Thats interesting, It's definetly a T350, I did the filter in it not to long ago. its not the funky shaped pan like the T400 on there other '72 3/4 ton. I wouldn't be surprised if it isn't original though, the motor and rearend aren't.
The truck is in overall pretty good shape, but theres some wierd stuff with it, like the block is black, heads are blue, and the valve covers are orange... Neutral

fiveoformula · Posted: Mon Aug 03, 2009 9:55 pm Post subject:

Is the 400 trans the same length as the long 350 & 700R4?

chevymad · Posted: Mon Aug 03, 2009 10:23 pm Post subject:

I think so. Think they did that so they could use the same drivelines and crossmembers but use different trannys. There's actually 3 different length th350s. The 67-72s usually have the short one.

fiveoformula · Posted: Wed Dec 23, 2009 12:45 am Post subject:

Haha, FINALLY getting started on this project. Got as far as taking the driveshaft out, and the cross-member (every bolt was tough, and a bear to get to.) Tomorrow, the T350 will be out, and the driveline is going to the shop to get shortened and rebalanced, Ill see if I can take some pics for you guys to see progress too.

john72ss · New Member Joined: 29 Dec 2008 Posts: 19

not sure if there is a "good 700r4?

aaron_sK · Posted: Wed Dec 23, 2009 9:36 pm Post subject:

They can be built nice, just ask Brandon.

Stock 700 + power + lack of TV adjustment =

fiveoformula · Posted: Wed Dec 23, 2009 11:31 pm Post subject:

I haven't been the biggest fan of the 700R either, but she'll be driving back and forth from Hillsboro to Klamath falls for school, and they have this working overdrive laying around. Should be put to use.

fiveoformula · Posted: Wed Dec 23, 2009 11:42 pm Post subject:

They ended up going with the TCI vacuum dealie for the TC lock-up.

aaron_sK · Posted: Wed Dec 23, 2009 11:51 pm Post subject:

Nice C20, dude. Thumbs up

Not very girly though, Laughing

You sure she wouldn't rather drive a Jetta?

Oh and no monster tach with the auto. That's just silly.

fiveoformula · Posted: Wed Dec 23, 2009 11:56 pm Post subject:

Thanks! it is pretty clean, just rolled over the first 100K. (tach was free) Very Happy

Lol this girl will NOT drive a jetta. Shes not comfortable with how "small" my firebird is... It's not like she needs the room either, she weighs 110 lbs. Rolling Eyes

Quasi-Traction · Posted: Thu Dec 24, 2009 12:18 am Post subject:

not to be too prodding, but is your girl going to O.I.T by any chance?

If so...she's a keeper. Thumbs up

Good luck with the swappage dude.

chevymad · Posted: Thu Dec 24, 2009 10:20 am Post subject:

Not a huge fan of the 700 myself either. I've only had one, the one i built for the formie, and I tried to build it as bulletproof as possible.

Always seems like the smaller the woman, the bigger the truck!? LOL Usually a 5ft nothing blonde in a lifted dodge diesel with 44s..

Al Hasse · Posted: Thu Dec 24, 2009 10:33 am Post subject:

fiveoformula · Posted: Thu Dec 24, 2009 8:47 pm Post subject: