Some Insight needed 14 Bolt\Lift Problem\Shaft\Vibration\Fitment

[2High4U]

I just got done with swapping out my 12 bolt for a 14 changed ujoints to the correct conversion u joint.

im getting vibrations going like 10 miles an hour havent gone faster than that cause i dont have brakes.

my lift block that i had were really big but it amounted to a 4 in lift im guessing the springs werent arched and it was just the blocks giving it the lift.

the blocks im using now are significantly smaller cause my ubolts wouldnt fit i got the blocks off of a trucks that had a rancho 4 in kit.

is it possible that the driveshaft has to be lengthend?

im going out to get the ubolts for my old blocks probably tommorow

the other thing that concerned me was that i had a hard time lining up the holes where the perches and the leaf springs met off by an inch to 2 inches had to pry on the leafs to bend them to line up. it fit well on my old truck with no problems so I dont understand where all this trouble is coming from.
the last thing is do the which way do the blocks slant i have them where the slant going up is facing towards the front of the truck.

any imformation regarding this can be very helpful to me.

 

[Hogback Fabrication]

Your rear end is from a 1 ton truck which has a slightly different spring perch width hence the trouble you had getting the center pins to line up. The taller end of the taper on the block should face toward the rear of the truck so it makes the pinion point up. The way you have it now, you are pointing the pinion down which is almost certainly causing the vibrations.

 

[2High4U]

Your rear end is from a 1 ton truck which has a slightly different spring perch width hence the trouble you had getting the center pins to line up. The taller end of the taper on the block should face toward the rear of the truck so it makes the pinion point up. The way you have it now, you are pointing the pinion down which is almost certainly causing the vibrations.

Is there a fix for the one ton rear perches in a K5 or would it hurt anything cause the other truck i got it out of was a 1500 with racho lift didnt have any problem when I put it in I also put the 14 bolt in that truck

I thought the opposite as you thinking that if the blocks were lower on the rear and tall to the front that it would move the pinion up just seemed to make sense to me that way. Ill go and try it the other way.

How much of a difference in measurment are the 1 ton 3/4-1/2

 

[Scott A]

1-ton: 40.5" perch spacing.
3/4-ton: 42.5" perch spacing.
1/2-ton: 42.5" perch spacing.