ok so this weekend im going to be installing my 5.5" iro long arm.(yes i will try to take pics and share ) one red flag i saw when reading the instructions is that i need a size "t" drill bit(.358") to drill the new hole in the unibody to then tap witha 7/16th-14 course tap. I have every tool in the shed and i get to use my dads radiator shop that has hydrolic lifts(yay). but the only thing i can't find is a size t bit. can i use a bit that is slighty larger than .358? i realize it has to be smaller than 7/16ths so that it can be tapped. thanks guys....

 

Yes you can... but on my Jeep the hole was already there just needed to be tapped.

 

Oh and I would cut your stock lca brackets off cause they well hit the iron longarms

 

Typically you risk breaking the tap (depending on the flute count and type; not to mention material thickness/hardness) but as bigjohnson (giggity) said, the factory left you a boss that's pretty much perfect to start with.

Ditto, I've got the IRO system at 4.5" and the driverside radius arm will contact the factory LCA mount if you don't cut them off. Not to mention, it looks better anyways.

 

harbor freight sells a drill index that has the "T" size in it.

 

Thanks guys. and I will cut the lca mounts wish me luck.

 

23/64!...its only 0.001" bigger.

7/16 -14nc should actually be a 'U' drill...

 

T= .358
9mm= .3543
23/64= .3594

 

"t" is pretty tight for a 7/16-14nc, sounds like pretty tight tolerance...like 0.010" under... hope you dont break that tap! good luck.