K-member swap and upgrades

**pajeff02** · 03-21-2012, 06:39 PM

After yesterday's alignment, I set the car up on the wheel blocks and with the suspension loaded I torqued the lower control arm bolts to around 95 ft.lbs. That's a little more than the stock torque recommendation but since the K-member is slotted and now has a combination of poly bushings and heim joints, I wanted to make sure that nothing moves around. I also marked the bolt heads on the lower control arms just in case something does slip. This will allow me to bring it back into spec very easily without a trip back to the alignment shop.

Out back, I had one cosmetic swap that I forgot to mention in my original list. The Moser 12 bolt aluminum cover came with black oxide button head bolts that had rusted. I had purchased replacements last year at Fall Carlisle, but came up 1/4" short on my guess at their length. I think it was Zapper who mentioned that Fastenal carries these in stainless and sure enough, I was able to find exactly what I needed on the shelf. I removed the bolts a couple at a time and replaced them with the stainless bolts so as not to break the seal on the differential cover. Once they were all replaced, I cross torqued them down in 3 steps to a final torque of 18 ft.lbs. The nuts on the bearing cap support screws are also a bit rusted, but I will deal with them later.

Winding up for the night, and having completed this round of mods, I snapped a pic of the entire undercarriage. It's been a great winter/spring project in the garage and everything went well, but now it is time to drive her!

**Zapper2003** · 03-21-2012, 06:55 PM

I think it might've been Dan that said about fastenal. Regardless, much better than rust.

**sjsingle1** · 06-15-2012, 10:25 AM

So how many miles ya got on it so far? still holding up?

**pajeff02** · 06-15-2012, 06:47 PM

She's been to the track twice and I have driven it quite a bit during the past few weeks. Had it out tonight for a run to the parts store and took a friend for his first ride in it. He actually flinched in the seat when I punched it -- that made me smile. So far, all is well and I am looking forward to swapping out the bumper support when I get a chance to work on it.

**silverWS6** · 06-15-2012, 08:16 PM

Wow! As always looks amazing Jeff!! Great write up! I don't understand why so much work into the decarbons though, get some Konis!

**pajeff02** · 06-16-2012, 06:18 AM

So far, the stock shock and spring setup has done well. I turned a best 60' of 1.69 seconds with it last year and the car appears to launch very well. Once I up the power, it may be time to break down and order shocks and springs. I still don't think I will lower the car, even though they do look better dropped.

**RichWS6** · 07-12-2012, 09:27 AM

Great write up! I am getting ready to do a K-Member swap as well, any advice?

**pajeff02** · 07-12-2012, 01:37 PM

The biggest issues were lining up the engine mounts and getting the GM backwards bolts removed. I would probably just start by unbolting the stock engine mount stands from the K-member and then getting that out of the way before attacking the mounts on the block. Take your time and keep track of things as you go.

**TA98** · 07-12-2012, 03:44 PM

Originally Posted by pajeff02

I would probably just start by unbolting the stock engine mount stands from the K-member and then getting that out of the way before attacking the mounts on the block.

thats what i did. the one side is a little tight with the ac but you wont have to worry about them being in the way when you drop the k member

***SMWS6TA*** · 06-05-2013, 07:10 PM

Originally Posted by pajeff02

I played with the motor mounts for most of the evening and finished swapping out to a set of Prothane poly inserts. I couldn't resist dropping the clamshells in the blast cabinet before painting them. The instructions are quite clear and you simply need to make sure that the tabs on the inserts are oriented correctly before bolting the two halves back together. The instructions call for 30 ft.lbs. on the bolts, however, I read a recent article in GMHTP where this was deemed too much as they snapped their bolts. I therefore snugged mine down to 25 ft.lbs. and called it good. The mounts were then re-installed onto the engine and torqued to 37 ft.lbs. There was some minor interference with the driver side heat shield on the clamshell bolts, however, a little bit of a bend and it went back on the studs and the nuts were torqued to 89 in.lbs.

Jeff, I'm fixing to tackle this soon. What size bolt & nuts did you use? Nylon lock (glare makes it hard to see)?

**pajeff02** · 06-06-2013, 03:36 AM

I looked again at the second pic up from the bottom and they are either nylocks or crimp locks -- hard to tell and I honestly do not remember. I am thinking that the nuts and bolts may have been included in the poly mount kit.

***SMWS6TA*** · 06-06-2013, 08:03 AM

ok, I guess it just needs to be strong enough to keep the poly in place. Thx's

**blackcar** · 06-06-2013, 02:06 PM

Originally Posted by pajeff02

I looked again at the second pic up from the bottom and they are either nylocks or crimp locks -- hard to tell and I honestly do not remember. I am thinking that the nuts and bolts may have been included in the poly mount kit.

Mine were included

***SMWS6TA*** · 06-07-2013, 09:13 AM

Originally Posted by pajeff02

I looked again at the second pic up from the bottom and they are either nylocks or crimp locks -- hard to tell and I honestly do not remember. I am thinking that the nuts and bolts may have been included in the poly mount kit.

Originally Posted by blackcar

Mine were included

I looked last night, the bolts are included...