hey guys and gals I know I lurk more than post but I know you guys can always answer the question of the day. I will be getting my Mac mids and ORY tomorrow and have a few questions. I tried searching and could only find the answer to a couple.
1-What header gaskets and header bolts would be the best? probably Felpro and Stage 8? if so please confirm.
2-What about o2 simulators? I know what they do and that I will need them with the ORY but will it hurt the car or performance if I did not put them in right away? or would it just be an idiot light?
3- what spark plugs and wires do yall recomend?
4- my z28 has eibach springs, sub frame connectors 3:73 gears and 17 inch rims. it is smooth and tight driving ( highway, traffic, etc. ) but at 80mph exactly it shakes so bad I have to slow down. even if I slow only to 75mph the shaking goes away conpletely. my suspension is tight, tires are aired up I cant figure it oput, so what I am asking is it normal on a lowered car or is something wrong?
I appreciate any answers or suggestions. sorry if i asked something that I should have found in the search.
Chris

 

As far as the shake goes, there is something wrong. This is not normal. This is usually caused by the tire shop not balancing to more than the speed limit. However it could be an out of round wheel, a manufactures defect in the tire, or other odd suspension problem.
I would start by taking it back to the tire store, have them set the balancer on "fine" and run it up to 90 mph. And have them use stick on weights not rim weights.

 

well since it's a LT1....it has the steel driveshaft...or better known as VIBshaft

they are WELL known for causing vibration at 70-90mph and up

i used the OE replacement metal gaskets for my LTs on my ls1

there will be no adverse affects on the car if you don't run the sims right away...just the SES light.

Taylor Spiro-pro wires are well priced, good quality and fit in stock looms. and just go for the $2 each NGK tr55 plugs gapped to .050", no need to spend 4x that on plats.

 

thanks for the replies, I will look into the drive shaft

 

What Tranny mount are you using? I heard if you install a energy suspension mount or the like that it changes the angle of the drive shaft and vibrates badly at high speeds because the new tranny mount is taller than the stocker. Just a thought. As for gaskets, I used felpro on my MACS and havent had a leak yet. And I used header bolts from autozone and none of them have loosened yet. I may just be lucky!

 

I agree with teke184, it most likely the vibeshaft. I replaced mine with the 1LE aluminum one and everything was fine.

Why do you NEED O2 sims?

 

far as i know it is the stock tranny mount.
the o2 sims would be because i will not be running cats

 

http://www.o2sim.com/24803.html

 

I'd replace the tranny mount, put in an aluminum driveshaft, and re-balance my tires.

 

My car vibrates at 80mph too, I put in an ls1 driveshaft and made the mistake of using the energy suspension mount.

 

thanks for the replies, speedy I will probably end up using that thanks.

Now, one more question, I received my Macs, they sent me a copper gasket, should I Use that? should I put sealant on it? or just be safe and get a Felpro?
I will post back saturday or sunday when the headers are in and let yall know what I think.
thanks again for the help
Chris

 

I would not use copper. Go with fel-pro.

 

thats what I fugured but I wanted at least on e other opionion, thanks

 

I used Felpro header gaskets, the bolts that came with my Jethots, ngk tr55's, Taylor wires, and Thunder Racing over the valve cover kit.

As far as the vibration, do you have any banging when you take off from a stop or between shifts? If so, you probably have a busted tranny mount. I would recommend going with a LS1 style tranny mount which has the interlocking design to prevent major banging if you break it (unlike the LT1 design which breaks into two pieces when it goes). The ES mount caused me major vibration problems.... I read about this "out of tolerance" issue with them after I had already replaced my driveshaft with a 1LE style aluminum shaft. That's why I now have a nice ES tranny mount as a paperweight .

Good luck running down the problem.