i currently have a 4" suspension lift with a tcase drop. im looking into an sye if i go any bigger (in terms of moving the frame away from the axels). i know the differences between a coil spacer and body lift are. there is no driveline angle change with a BL, but there is with a coil spacer. that being said, i am looking into a few more inches of height.
what do you want - a 4" lift? or 1" BL? or a coil spacer lift? They are very different things.
Once you go over 3" of lift, you really get into SYE territory. Coil spacers lifts only go up to 2.25", and most times you need to do a small t-case drop to eliminate vibes with that height.
1" BL is a body lift...it lifts the body away from the frame.
You can combine a 4" lift with a 1" BL, to clear 35s (assuming you've done everything else like bumpstops, shocks, brakes, steering, etc, etc). This is expensive, but works well.
Or you can combine a 2" spacer lift, with a 1" BL to clear 33s. Which isn't a great way to go, but it's cheap.
Some people combine 4" lift springs with 2" budget boost (coil spacers), but they're morons and don't understand the implications. Don't do that...just buy a 6" lift kit if you want 6" of lift.
fixed it for you
You're the first person I've heard say an SYE may be necessary at 3" of lift or higher (and usually tcase drops aren't necessary at 2" or less)...most folks say it starts to become necessary at 4". I spoke with the folks at Zone Offroad about their 4" lift and they even told me that combined with their provided tcase drop, they haven't heard of anyone having any problems with vibes or having to switch to an SYE or something along those lines.
To whoever said that an SYE isn't necessary with coil spacers, if your spacers are combined with another lift, I'm pretty sure that could put you into SYE territory depending on your particular vehicle and the amount of lift it'll have between the two lifts.
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