When I drilled mine, I used a center cutting end mill. That and a Bridgeport, but I would think a heavy drill press would do the same thing. I was surprised at how easy they were to drill. I always thought they were made of stronger stuff.

Yeah. My small drill bits went right thru, but when i got to the 1/4" going in small steps would not drill or cut any more.

The end mill did it in one step.
If you burned up a lot of bits, you may have hardened the metal right near the hole.

if work hardened by using too fast of a speed drilling, a carbide endmill or drill is your only option now to finish the hole. most guys go way overboard on the rpm of the drill [especially with a hand drill], and tend to burn up the cutting edge, even with quality bits.

I was using a drill press. I may just run them down to the machine shop tomorrow.

a cheap glass carbide drill bit with a little luck could work,and slower speed

Bought a set of Milwaukee cobalt bits for hard metal. Wouldnt touch it. Looks like i will be dropping them off at the machine shop down the road. Thanks guys

drille a hole on the perch instead!

Probably should have, but dropped the springs off this morning. First shop turned me away.

I'm really second guessing this now. I dropped off the original front sections to the mono's which are 1/2" longer and 1.5" arch. The extra front sections i have are 2" arch and look to be heavier duty. Which front sections do you guys think would be best to use at getting this 511 hooked up at the track? I could just drill the spring perch and use the shorter heavier spring real easy. Thanks

Sorry to see this is giving you such a problem

Do you have a spring shop in your area? many towns do.
They're used to doing HD truck stuff and may be able to advise you on this.
I hope it works out for you!

Its really not that big of a deal. Just curious if the heavier spring would be the one to use with my current combo. The original springs were installed when i had a small block

you were absolutely right. My drill speed on my drill press was too fast. Today i tried my fathers drill press which is set up with a slower speed and we drilled right thru without too much trouble. Springs are now installed and maybe tomorrow i can finish that up and get the car on the ground. Thanks

Speeds and feeds will get you every time. Glad to see you got it sorted out.

Thanks. I decided to use the shorter heavier front segment. Maybe this will help with getting it hooked up at the track.

an interesting story regarding speeds and feeds. my brother installed a railing in a house he owned one time. just one of those cheapy, imported, lumber house specials. not thick steel by any standards, maybe .094-.100 at best. all the holes drilled ok until the last one. it was a real toughie ! my brother thought it was a combination of imported steel, who knows quality of the bit, and the fact there was many holes drilled with a used bit to start with. anyway, he just gives it all he got and finally, got it pushed through [hand drill of course]. the hole looked like he used a torch of some kind to blow it through, and the drill was "slightly" deformed on the tip. he had the drill wide open, and was pushing with all he had. one spin of the drill to cool it off some, and yep ! it was in REVERSE ! i still jack him about that from time to time !

So the shorter spring allowed you room to drill the hole away from the factory hole?And still move the axle back as intended?

Yep. only had to move it 1/2". Dont see issues yet.

You should be ok,The axle windup/shock controle is key.