Is there any type of drilling or modificatiion required to install these or are they straight bolt ins?

 

it is pretty much straight bolt-on.

 

Don't waste your money on the bolt-in model. They recommend welding the bolt-in model, anyway. Why pay more for a powder coating that's going to get ruined in the process. I ordered the weld-in. They bolt in as well, and then you weld around the edges. They honestly don't look any different except for the powder coat. Spohn has the best deal on weld-in style. GMHTP installed some bolt-in BMR units on the Grape of Wrath in the issue previous to the latest. They recommended welding them, as well. Crazy, I say. It's nice to own a welder and be able to do your own welding.

 

Do the weld-in ones requires any type of drilling or modification to the rearend?

 

As far as the BMR bolt-in bracket goes, BMR told me that you could also weld them, but would only really need to if your car was in the 10's or you were pulling 1.5 60' times. If you want to be able to remove them some day, just get the bolt-in ones. Sure, the weld in ones are the most secure option, but you have a choice if you want it and don't need to weld unless you have the specific need.

I find their bolt-in design extremely secure and they have not budged since I put them on 1-1/2 years ago.

 

I have the bolt in and I open track my car at the road course and have never had a problem.

I check the bolts before each event, but I have never even had to tighten them.

 

No. They slide over the stock LCA brackets and the edges get welded together.

SPOHN WELD-INS

 

Will the help with traction? or are they just for lowered cars.

 

If you are making decent power, they will help a lot on a stock height car.