700r4 shifting problems and swap advice wanted

[Madtrucker]

I recently bought a 72 blazer with a 350/700r4/np205. According to the spid it originally had 305/4spd/np205. The 700r is giving me problems with short shifting from 1/2 and not up shifting into 3rd. There's no slipping or high reving it just stays in second and drives until I back off to keep the rpms reasonable. I have re geared to a 4:56 and realize the governor needs calibrated but don't see how that will fix 3rd gear. At wot it shifts at about 2400. All the trans shops are 3-4wks behind and I'm trying to keep my blazer going for the season. If no one can help it's on to plan B.

Plan B would be to swap the 700 for a 350, my question is how can I tell if my 205 was mated to the 4spd or came from a 350 trans. I don't know what was modified to fit, the 700 or the tc. All I know is there is a advance adapter spacer between the to. I'm not looking to spend $1700 or I'd have the 700r4 rebuilt so any help would be appreciated.

And I've looked locally for a 350/205 combo with no luck.

[Madtrucker]

Anyone?

[andrewmp6]

There's a few ways to do that trans swap,To know how it was really done pull your t case and count the input spline.There is a 10 spline a 27 spline and 32 spline.

[IIGW]

Originally Posted by Madtrucker

I. I'm not looking to spend $1700 or I'd have the 700r4 rebuilt

Anyone who is quoting 1500 to rebuild a 700 should stop drinking.
Pulling the overdrive trans out and putting in a 350 on 4:56 gearing will be like 3500 rpms at 65mph.
I don’t have my 700 manual with me, but if I were you id find another trans shop. Also, google the shifting problem ad im sure you will get all the answers you need asap.
Long run, that 700 is a non-electric version of the 4l60e. a good trans, with overdrive. Id keep it. In fact I have one in my 1 ton dually, on 4:11 gearing, and around 600hp at the motor.

[57taskforce]

More than likely the 205 at least has a th350 adapter on it. Only way to really tell which case you've got is to pull it and count the input splines on the case. The easiest way to mate a 700r is with a 350 adapter and case. The easiest way is a 2" spacer between the trans and transfer case adapter, and longer bolts. although there are a few ways to skin this cat so it's hard to tell how yours was done without seeing it.

[Madtrucker]

Thanks guys, Google has only led me to slippage problems in 3rd which I don't have. Trans doesn't slip, engine doesn't rev like there's no load, no burnt fluid.

The 1700 was more like a start over scenario like new trans, another tcase, driveshafts etc. I just figured someone would chime in with something like that.

I'm looking for a good local shop this week, hope it works out. Seems like people love or hate the 700, probably has a lot to do with the quality of the rebuild and installation. Seems like a lot of people throw them in and don't adjust the tv cable properly. Mine had a 350 kickdown cable rigged, but I changed that immediately.

[Madtrucker]

I didn't mention I have 35" tires, so I don't think it'd run that high. I'll definitely calculate what it would run at with the 350 though.

[1malo68]

Sounds to me like some sort of adjustment. Here's some good info that might help. I would definitely check the adjustment on your TV Cable to start with. Good Luck!

http://www.transmissioncenter.net/subject.htm

[Madtrucker]

Thanks for the link, it seems to be set right but could be to late i suppose. I'm a little leery to try the 100mph test.