I am building up my L67 for my T and was planning on a XP cam. Well when talking to ZZP they said 105 springs and modded retainers plus a Double roller Timing set. That is what I purchased but recently discovered that I had to remove or at least disconnect the balance shaft which causes a lot of vibration. I will be driving this car a good amount, pretty much daily for at least a couple years. I am thinking about going with a single because I have heard of others running a single with no issues.


I just want to hear your thoughts, opinions on the matter. If I do go back to a single, any suggestions on which one?

Also other than the cam, modded retainers and springs (plus i got new valve seals) anything else that I will need for the cam install. Keep in mind I have a new complete gasket kit so that part is covered.

The only thing I can suggest is to try to find someone who has their balance shaft removed and see how bad it really is, a bad vibration is very different from person to person, I had a 1990 Talon that I removed the balance shafts from and it would shake stuff out of the cup holders at an idle but I loved it.

I believe boostedponty has his balance shaft removed.

To run a double chain you will need to use 2 gaskets on the timing chain cover, or a milled down oil pump cover, .020 needs to be shaved off.

Do you need a double chain to run a cam and #105? No, I'm running on a single chain with that set up.

What do you need? ZZP has a cam install kit, it has all you will need. I think it was kit 4 I went with. It has everything. I didn't need anything else other then some black RTV.

How many miles have you put on the car since the cam, springs, etc were installed? I will be driving daily with some track time once in a while and I don't want to have anything break and have to deal with either replacing these parts again or worse, destroying the motor.

Over 2 years on the springs, about 2 months tops with the cam. I was running 1.9:1 rockers for over 2 years. My friend is running a XP hot cam with #105 on a single roller chain for about 3 years. You should only have to worry about a double roller if your going with #130 springs. When you install the cam, make sure you get a new timing chain, the kit will come with a new tensioner.

Stock single chains are plenty there'* a purple fossil roaming around who has an aggressive can, 130# springs and 1.8 rockers. He'* broken everything but the chain.

It'* going to sound like I am ZZP bashing. I am not, but have many issues with their sales practices and some of their products. I am trying to point out where other products are preferred.

ZZP double talks all over their site and forum. They are a business and try to increase sales anyway they can. While I do like many of the parts they sell, I absolutely despise their sales practices that go as far as telling customers when things break that it'* an installer error or they've never had a problem in the last X years or X number of them being sold. That'* simply **** poor customer service, kinda like not including cam lube in a cam install kit. They know how to **** off an installer.

There are hundreds out there running XP cams on single chains. I installed one this weekend. Get a new stock chain or single chain and you will be ok with 105# springs. Watch out which retainers you get, ZZP'* modded retainers with their modded rockers and HD valve locks will hit. My suggestion is ZZP valve seals, Intense'* Manley retainers and Crowe Cam (ZZP or Intense) 105# springs. Comp Cam 105'* were sourced to Mexico a while back, then started breaking. Get the chain, dampener and reuable rocker bolts from either. Gaskets... ZZP'* valve cover gaskets don't seem to fit properly (I put a set on this weekend) and don't come with the grommets. Grommets are there to keep the proper torque on the gasket, they should be replaced when changing gaskets. The gaskets from ZZP were slightly too small for the valve cover and had to be stretched to fit in the channel, I have never found this with GM or FelPro gaskets. Thought if was extremely odd, maybe they have some other manufacturer making them.

A disconnected balance shaft is a lot of vibration in a 3800 motor. Don't forget your RTV and pipe sealant for the LIM bolts. With the right parts the install goes quick and easy.

BTW My car is an informed owner taking a bit of a chance. Typically on 130# springs you would have a double roller. I, like Todd Allen at Intense chose to keep the balance shaft because of the vibration and therefore am limited to a single chain. Soon I will be checking for issues or stretch, until then the car is my toy and it'* an informed chance that I take.

Thanks Bill. After debating and asking on a handful of forums I have decided to go with the single and hope for the best. I think it should be ok. I just dont want to risk hating the vibration so much I have to switch it out 6 months later.

The one guy I know that removed his balance shaft said it vibrates a bit at idle, but then goes away once the RPMs go up a little.

I've heard of and felt the vibration. On a mostly balanced engine it was more than I would want. On a non balanced engine it made me feel like I was in a built V8 without any exhaust and the headers dumping below my feet. About 10 minutes in my feet felt numb. You should be fine sticking with the balance shaft. Rick Aka DeMonte has XP with single, toss him a message.