I don't really want to get in a pissing match, but I disagree completely with you and assert that your recommendation will cause poor handling and actually result in damage to anyone who follows it and wheels their rig with a fully flexed suspension.
First, at 3.25" caster will be less than 2 degrees. In fact, many have reported caster in the 2 degrees range with just a 2.5" lift. As a result, nearly every reputable
manufacturer that sells lifts over 2.5" either includes or recommends either cambolts, front lower control arm relocation brackets, or front lower adjustable control arms.
Low caster results in flighty steering and wobbles. Spec caster is in the 4+ degrees range.
What is your caster spec with a 3.25" lift and stock arms?
The stock yellow bumpstops are relatively soft. As a result, when measuring available suspension travel you need to measure from the metal lip of the bumpstop cup to the lower spring pad in the front and the bumpstop pad in the rear.
Here are stock front bumpstops with flat flares, 4.5" backspaced wheels and 35s:
Even with 2" front extended bumpstops, 35s will rip off pieces of the front flare plastic support skeleton for stock flares.
A fully compressed front bumpstop with stock flares and 35s will actually cause damage.
If stock bumpstopping were sufficient to run 35s without rubbing on stock flares, you could run 35s with no lift.
Also on extended bumpstops, one of the purposes is to prevent your springs from overcompressing. Stock bumpstops will not prevent 3.25" springs from overcompressing.
Please show a fully flexed out suspension (yellow bumpstops compressed by at least 1/2) on 35s with stock flares, no body lift, and stock bumpstops with the amount of clearance left.
Regarding flat flares and 37s, here is a compressed rear suspension with 2.5" extended bumpstops, 1" body lift and flat flares (and you say that someone can run 37s on stock bumpstops and flat flares with no body lift that would reduce the clearance by 3.5" when flexed):
Also with 37s, here is stock front bumpstops not entirely compressed and overcompressed front springs, with flat flares, and a 1" body lift (You say it will work without the body lift. So, where is the extra 1" clearance from no body lift and extra almost 1" travel from completely compressed front bumpstops?):
Shocks sufficiently long to run 3.25" springs require extended rear brakelines.
Here is a fully drooped rear suspension on shocks for a 2.5" lift with 2.5" rear extended brakelines:
Without the extended rear brakelines, the shocks appropriate for a 2.5" lift would have overextended the brakelines at full droop--causing damage.
Please show a picture of fully extended shocks appropriate for a 3.25" lift with no extension to the stock rear brakelines.
The automatic transmission pan on a JK has low clearance to the stock front driveshaft boot. When the suspension flexes beyond the droop of about a 2" shock, the driveshaft boot comes in contact with the transmission pan and rips the boot.
100% of my friends who have wheeled an automatic JK on a 2.5" or taller lift have torn their stock front driveshaft boot on the tranny pan within their first few wheeling trips.
Even without an automatic transmission pan, shocks that are sufficiently long for a 3.25" lift will allow the stock front driveshaft boot to rub on the exhaust system that crosses infront of the frame crossmember. This will rip the stock boot if there is any meaningful forward or back motion--causing the driveshaft boot to spin on the exhaust system. Most people do not flex out their exhaust system that much for this problem with the exhaust, but those who do will rip the boot.
Fifth, swaybar links.
I missed it before above, but the Rusty's kit does not include longer rear swaybar links (added to the missing extended bumpstops, and brakeline extensions).
With a 3.25" lift and stock rear swaybar links, the geometry of the rear swaybar is all out of spec. The links should be long enough so that the swaybars are a few degrees higher than level. With too short rear swaybar links, the rear shocks will not be able to fully droop (maybe this is why none of you or your friends have ripped out your rear brakelines yet).
Too short rear swaybar links will cause "jumpy" handling on turns and will not fully allow the shocks and springs to do their job when cornering.
The shipping of the Rusty's to me in Montana is $91. So the Rusty's kit would be $641 shipped--without extended bumpstops, brakelines, or rear swaybar links. I suppose someone who is closer would pay less shipping.
The cost of the TF BB is $380 including shipping
. The cost of the 2.5" coil lift with shocks is $631 including shipping
If you add the missing components to the Rusty's kit and a JKS front trackbar to the Teraflex 2.5" spring lift with shocks, the difference in price is less than a full tank of gas.
I like Rusty's and have ordered from them in the past. They have always provided good service and been very responsive.
However, I don't like it when any manufacturer sells a kit they know is incomplete and will cause problems.
Also, as a quality comparison:
The JKS front trackbar uses Clevite rubber bushings instead of poly bushings.
Also, look at the size and strength of the adjustable ends comparing the JKS to the Rusty's: