[UnchainedGTO]

I have a 400 that is about to be reasmbled and am contemplating a cam change. The car is a stock 68 GTO with a 30 over 400 featuring forged flat top pistons. The only changes in from the oringial specs are that the car has been running with a 3:55 rear gear and HS 1.65 roller rockers. It has the stock log style manifolds currently and I don't see making a change in that area at this time.
Does anybody have a suggestion on what cam to put in?

Thanks,
Unchained

[UnchainedGTO]

I have a 400 that is about to be reasmbled and am contemplating a cam change. The car is a stock 68 GTO with a 30 over 400 featuring forged flat top pistons. The only changes in from the oringial specs are that the car has been running with a 3:55 rear gear and HS 1.65 roller rockers. It has the stock log style manifolds currently and I don't see making a change in that area at this time.
Does anybody have a suggestion on what cam to put in?

Thanks,
Unchained

[berrygoat]

Those manifolds are big limting factors. I would run either the Factory 068 or the E-Performer cam.

[Mr_GTO]

Lots of new computer designed cams to go with. Why go with a 40 year old design?

[berrygoat]

For someone on a budget, both cams are cheap.

[Brian Baker]

The 30+ year old designs still WORK in applications such as this one mentioned, that's why. But is a newly ground 068 the same as one ground 30+ years ago? Probably not.

[UnchainedGTO]

Guys,
Thank you for the responses. I am going to stick with the 068 since that is what I have and it seems to be working pretty well. I am not opposed to making a change down the road, but time constraints are making the call at the moment.

Thanks Again,
Unchained

[Mr-Bratt]

Unchained.
I was using the 068 cam in my 75 400 and t was just ok in my opinion. I ended up switching To the NUNZI 2041hl Its a 068 cam tweeked to nunzi specs (search on my name for my cam choices post) And I have to say WOW what a difference. This cam really woke that engine up. So I would have to say that would be a great cam for you? Good luck with whatever you decide, Mr-Bratt

[UnchainedGTO]

Mr-Bratt,
Thank you for the advise on the Nunzi cam. I used a Nunzi version of the 744 years ago in a 69 RAIII 4 speed Judge and it seemed to work pretty well. I am trying to keep this car close to factory specs, but I am willing to make minor changes as needed. I don't know if running the HL version of the 068 will be too much with my stock exhaust manifolds. I will also need to check my spring height.

Thanks Again,
Unchained

[Will]

My guess is that performance won't get much better than what can be achieved with the 068 as long as you're running stock exhaust manifolds. You could try some high-ratio rocker arms. 1.65 arms would likely be compatible with the stock springs and *might* not require opening the pushrod holes in the heads either with that low-lift cam. But, that's only speculation, you won't know 'til you try them.

Mr-Bratt, were you running headers or stock manifolds?

FFCC, nearly every new "computer designed" cam I've seen employs tighter lobe separation angles to increase overlap in order to punch up midrange power. Dyno tests have shown numerous times that this isn't a very good strategy when running a restrictive exhaust system. Most aftermarket manufacturers expect you to upgrade your exhaust. The factory engineers were well aware of the limitations of stock manifolds and designed their cams accordingly, so like the other Mr. Baker says, these cams still work well in the applications for which they were designed.

Cheers,
-Will

[Mr-Bratt]

Will, to answer your question, Yes I have headers on the car with a few other mods as well, It just slipped my mind about his exhaust manifolds. oops [img]/infopop/emoticons/icon_frown.gif[/img] But as for the 1:65 rockers even with the 068 I had to open up the pushrod holes in my 6x heads. Mr-B