Auto-Manual Swap

[kefla41]

I was wondering how much work is involved in going to a 5 speed from my automatic for my '85 K5. the 350 turbo 3spd is useless in travelling on the highway and i hate auto's anyway.

 

what kind of 5spd would work best(prices too), i've got a 305 in it right now.

[mjsmith1223]

Just curious, why is the TH350 not working for you? In my GMC it does a fine job. If it's mileage your after, maybe a swap to a 700R4 would be simpler?

 

Off the top of my head I'm thinking the crossmember will probably be different, flywheel will have to be put in, flex pate comes out, drive shaft might be a different length (not sure on that though), your rear-end gear ratio might not be appropriate for a manual. If you have a 2.73 rear end now, you may need to go to a 3.42 or 3.73 to be happy with the manual. Oh, it's 4x4 (K5), so there will be transfer case issues and if the rear end changes, the ratio in the front differential has to change to match it. Also would need to put in a clutch pedal and all associated linkages, and cut a hole in the floor of the cab and mount a shifter. You might find all the parts from a manual truck in a boneyard somewhere. At least that would save you a few bucks.

 

There's a mutitude of 4/5/6 speed tranny's that will work. Check out Summit or Jegs for a sampling.

 

Hope this helps get you started in your planning.

 

Mike

Grand Haven, MI