Transmission Questions
 

I have an 88 350 3/4 ton suburban with an ailing 3spd. turbo 400 transmision. What all would be involved in the swap to a 4spd. overdrive 700r4? I no longer tow with it and would like the mileage benifits of the extra gear. I know half tons of this era were equiped with the auto 4spd. Are the transfer cases and related linkage the same? I am kind of hoping this is a bolt in deal.

Re: Transmission Questions
 

well on a 4x4 i'm unsure i know the 700r4 has a different length to it but i'm not sure what all is involved i see it done but in reverse to how your doing it you will have to setup the kickdown cable on it since the 400 is electric kickdown

Re: Transmission Questions
 

You will have to change the input gear to your transfer case. The t-cases that were behind th-350's and 700R4's have a 27 spline input and the t-cases behind th-400 & SM-465 have a 32 spline input. I'm not 100% sure, but you may also need a different trnasfer case adapter too.

Re: Transmission Questions
 

Thanks for info guys. I really need to find a half ton equiped with a 700r4 and do some investigating. I don't really want to spend a fortune because my suburban is rusty. The trans. does have to come out and while it was out I thought I would upgrade. I really like this body style and don't really want to buy anything else at the moment. I might be better off finding a less rusty half ton with the 700r4 already in it.