scorpio333

I've got a 12 FX4 and raised the front 2" and put a 2" block in the rear, still sits 1/8" lower in the rear. While searching for add a leafs, blocks and doing a lot of math I came across an older post where someone claims the Raptor rear blocks are 2.5". If someone here could be so kind to climb under their beast and measure it I'd be very appreciative.

All The Way

Not with Hurricane Sandy dumping her misery on us I can't. Maybe someone clear of the storm can.

scorpio333

No problem...stay dry. I found a couple mentions of a 2 1/2 to 2 5/8 tapered block and a pic in this review. Now that I have that info I can't find a part # for them. Tasca shows the rear blown up, but no blocks anywhere. That is unless #7 U bolt shim is the block, which I doubt.

Steeda

Ill look and see if I can get you a measurement tonight

scorpio333

Forgot to update this...I got the measurement. Bought a set of blocks and u-bolts off another forum and installed them. Sits right where I want it now.

The blocks are 2 1/2" on one side and 2 5/8" on the other - I assume this taper is for pinion angle. Everything fits but they're a bit of a PITA to install due to the bump stop 'wing' on the side. They tip over so it's a back n forth game with lowering the spring/and wedging something under there to line up the locator pins.

Hammer40

Does the larger side point to the rear to adjust your pinion angle?

scorpio333

They are shorter on the front/taller in the rear. I'm speculating it's designed that way for pinion angle, I could be completely wrong. It could also be to support the leaf pack at a better angle due to the height difference over the regular 1.25" OEM blocks. Maybe it's an axle wrap/wheel hop issue. Whatever it is the SVT team did it and I'm pretty sure they wouldn't have wasted their time without some reasoning.

The other question is if Ford did it that way for a specific reason then why don't the aftermarket companies who make the 3" and taller blocks? I've not seen/heard/read of anyone having issues with shock travel, pinion angle or leaf packs when running those 3" blocks.

By no means would I consider this a complete explanation...it's merely one data point. Read #5
http://www.truckaddons.com/Catalog/s...erlift_FAQ.htm

Hammer40

That was my understanding as well. I have 3" blocks and ended up adding shims after determining my pinion angle was off. I was reading conflicting data on which direction to install the shim. Your explanation confirms what I thought.

-Jeff