4 link bar measurements

Can someone explain this to me. How do you determine how long or short your bars should be for the 4 link. Please help!!! Oh and if it matters its on a 89 b2200 ext cab

im not to sure but i dont think the length matters as much as the positioning. i bought a universal link and put it in and they work fine. you just want the top link bars to be at like a 45 degree angle or so. thats about that mine are

Its all up to you how you set up your links. The longer your bars are the better your pinion angle will be throughout travel.

I really like this guy's set up:

His bar lengths are:
Top = 29 1/2"
Bottom = 26"

you just have to determine how much lift you want, if your just running bags over axle then short arms are fine but if you want the grasshopper lift then youll need longer bars. the longer bars keeps your pinnion closer to the proper angle with more lift

More:
Pinion Angle
Why Reverse 4-Links Suck

If the top and bottom bars are equal length, the pinion won't change no matter how much lift you get out of them. Ideally, you want to keep them as equal as possible. The longer you make them, the more centered in the wheel wells they'll be throughout the whole travel. If they're too short your wheels will look like they're pulled forward in the wells either when layed out and or at full lift.