350 / 6 cyl perches / 700r4 ?

[Skirkpat]

I am getting ready to put a 350 / 700r4 in my 69 Suburban that has 6 cyl perches and a 3 spd saginaw now, I am looking for the easiest/cheapest way to get the MTR / TRAN in right now.

1) I have read that I need to shorten the driveshaft 3 inches?

Can I move my 6 cyl perches to the forward holes and keep my driveshft the same length?

I think that I will need to get a different splined yoke, is it as easy as grabbing one off of a 87 or 88+ model?

2) Would it be easier to use V-8 mounts off of another truck?

Thanks for the help...