700R4 in my K10 long bed

[Michael D]

I am replacing my 350TH with a 700R4. The shop doing the work is a reputable shop but I want to ask a few more questions.
He is looking at moving the NP205 back to accommodate the additional trans length. That requires modification to both driveshafts, add and shorten.
Ive read people have moved the engine forward to accomplish the same thing without modifying anything else.
Has anyone done what I am intending to do? Any regrets or positive feedback?

[Zoomad75]

The 205 is moving back not because he wants it to, but due to the longer length of the 700 over the 350.

The problem you get into moving the drivetrain forward is the cascade of other things you have to deal with for that change. Off the top of my head there's a few.

Factory shift linkage will need to be modified or ditched for and aftermarket shifter setup.

Fan to shroud position will be too deep and will effect the cooling. It might get close enough to put the fan too close to the radiator. Might have to ditch the fan completely and go electric.

The exhaust manifold or header outlets are going to move forward with the engine. Which will require fixing too.

There's more that would have to change, including the engine cross member.


So it's a simple run to the driveline shop to get one shortened and one lengthened or a bunch of other modifications. It's cheaper in the long run to just get it done instead of moving the drivetrain forward.

[dennislbrooks]

I agree with Z.

You may get by with only the rear drive shaft needing shortened 2 inches. The front shaft may have enough slide left - dunno. It will probably be less expensive and less problems in the long run to moved things back.

I did like the extra engine clearance on adding a bbc by moving it forward - much fabrication.

[Michael D]

ok, thanks, I was planning on the route I mentioned but I didn't see anybody modifying their drive shafts so I wanted to get some reinforcements. Moving the engine didnt seem right to me.