1970 383 cam suggestions?

I'm happy with the lunati voodoo cam.the 480 ish lift one.My car performs/ behaves much better than it did with the mp 509 cam.idle is not very lumpy,does have a slight attitude sound though.

with moretoys i'm using the Vodoo 220/226 @.050 475/494 lift cam idle's like a stock RR cam, lots of vacuum 17.5" at about 850rpm's on my 4-speed power brake car, lots of low to mid range, rev's very fast. happy with it.

Why would you put your vacuum advance to manifold vacuum?

the Comp 268 or the Crower 267HDP are great 383 replacement cams and will give you the idle characteristics you are looking for. The Hughes you had is just a smidge big for a mild 383 but before tossing it I'd try a set of Crane or Lunait Hi-vac lifters, should knock about 6-8 degrees at .050 and pick up vacuum with no downside...I've run them in 11 second cars so no worries there.

Haven't run the Voodoo but being Harold for Ultradyne developed them that speaks very well for their pedigree. I've been happy with Lunati's before as well.

The MP 455 lift 268/272 Purple shaft is another good one

My cam suggestion is in....My retort would be why would anyone run venturi Vacuum? You want advance to come in under load and part throttle, high RPM speed the centrifugal kicks in. Manifold vacuum is where you want it 95% of the time anyway.

I tell people 383's are more like smallbocks, they're easy to overcam if you're not careful Gotta watch the intake closing event especially....go too far and you'll take away what little stroke you have to work with.

also....since it's not too big....you might try advancing it +4 before swapping it out...that'll help your vacuum and low end...just a thought.

Id say try the 455 272 Purpleshaft suggested before.

P4452783....the restro cam, works very good for me, everybody says "old grind", but, its an old car!!, plenty of vacuum for my PDB, great idle and no chugging at the stop signs

Here we go! Although there are many who will disagree
No sence typing out the proper method of getting it to run right with my two fingers then!
Good luck

Ok first and always unhook he vacuum advance and plug the port coming out of the carburetor. Forget it is even there till everything is running right.
Now I agree with above that lighter advance springs would help but you can add them later in the process.
Now set your total advance to 36. (2500 to 3000 to get max mechanical advance all in) Set your carb idle and go for a drive if it pings a little under light and or heavy load retard if it don't advance it to 38 if still no ping good. now if you still don't get the idle you want you will have to add lighter advance springs (one at a time your cam is plenty mild) to get that 20 or so you are using manifold vacuum to hold advance up to at idle. Now if you are getting the idle you want and no ping you are almost there.
(right now you are getting no ping as you are using manifold vacuum to hold timing up for idle but under heavier acceleration your manifold vacuum drops to 0 or near 0 so your total advance at that point is likely around 20 total way off optimum for power and performance)
now drive for a few days till you are sure you are happy with all round performance and idle quality.

Dam I forgot about that pesky vacuum advance!! LOL!

Now vacuum advance explained. vacuum advance is a gas mileage enhancement device designed to work under light load part throttle conditions. say your doing 65 mph at 3000 vacuum is high and throttle plates are slightly open exposing the ported vacuum port to manifold vacuum. This will cause the vacuum advance to pull on extra advance 45 to 52 deg total giving more power with less gas applied (and therefor slightly better cruise mileage.) Since cylinder pressures are low no ping. But alas this was designed in the days of 102 high test and regular at 98 octane!! Todays fuels will not allow that much light throttle advance.
So you must limit the amount of extra light throttle advance the distributor allows by 1, forgetting it and going on with you life. 2 tuning it out with a 3/32 allen wrench in through the vacuum post. now driving it with vacuum hooked up if you are experiencing ping you put 3/32 allen wrench in through that port and turning counterclockwise start eliminating the amount of vacuum advance that can be applied 4 turns first then a couple at a time till all light throttle ping is gone then your done.

I say just get your advance curve right for your cam and forget the vacuum but??
if you want it to look hooked up just block vacuum line inside.

I too years ago got on the wrong path with manifold vacuum. but would recurve distributor and tune for max hp and ET. and leave it unhooked now I understand how it should be done when i recurve friends distributors and get things running real good most don't want to bother with the vacuum advance for the ever so slight gain in cruise mileage if any with todays fuels.

Please go back to square one and try this method you will thank yourself and biggest outlay will be
$11.95
MOPP2932675
or
$4.95
MRG925B
not as light and a little time.
reset carb again in the end and you will have more power and better all round drivability

Thank you,

As i said, the engines on the stand and getting torn down. Aside from the cam there is a noise I'm not comfortable with that I need to fix. I can not afford to do this again so it's extremely important that I make the correct decision with another cam.
Before the switch to manifold vacuum I adjusted the timing to have around 36-38, I believe it was all in before 2K IIRC. It's been a while. The initial ended up being about 20. When idling it had only about 11-12 inches of vacuum and ran eye burning rich along with the other symptoms I mentioned earlier. The cam was degreed when installed.
My car is only street driven and will NEVER see the track or abusive driving. I am more than willing to try your approach after it's reassembled.

Stepson just replaced a 284/484 with a Comp XE268H. First ride had him gigglin'. Great street cam. For more details P M jlhram.
Ron

That cam is plenty mild why spend more money. lighter advance springs will get the idle better. If pulling the idle advance up made it better doing it right wih light spring is the same thing done right. (but this causes an advance retard condition under heavy acceleration)
As I say many put a cam in then struggle with idle quality go to manifold vacuum to pull more idle advance and think that is the way to go and I suppose it is if your happy with 50 to 100 hp less than the motor will give??

I would for more bottom end idle and low power advance it from where dave recomends (108 intake max lift / centerline) to 105
Trust me and start it with at least one lighter advance spring installed right off the bat.
Stick with this cam if in the unlikeley event you cant get the idle right cam install just means taking out the rad and maybe the grill

May be a difference on what you call noisy and what I do. It's not much of a cam is it ticking a bit???

hard to hear any ticking w/ my foot to the floor and the 2ndarys wide open.

hej,so what cam did you end up with,how is it to drive.

Gawd, I love your car. Tough to find a '70 SS that isn't beat here on the East Coast.

That looks so close to my underhood I thought it was my car. Except yours is much cleaner. Is that FK5? Mine is in an ebody.

I'm running the stock grind cam and love it. Plenty of power and great idle.

Side note: I'm pretty sure that dipstick tube should not be painted.