For a 4x4 I have a 390FE right now. It's got about 6 hours breakin since a full rebuild and is back stock. So I figure while the truck is getting restored and the engine is out I'll pull the front of it apart and put in a new cam. I want it to give me more throttle response and torque but at the same time I want a nice nasty sounding idle through some Race Bullets. So how does this cam sound? (216/216 duration .533/.533 lift) I can get the cam/lifters/lube for about 120 bucks so that aint bad at all. Will my stock valve springs work fine with that cam since it isn't a huge cam? I'm guessing it will but if not I guess I'd need to upgrade. I'd just prefer to avoid that. Also I think I will use the stock HiPo 4 barrel cast iron intake. Maybe polish it somewhat and portmatch it to the heads. I am also going to do a port and polish job on the heads and match the heads to the headers. The bottom end I wont even touch but I also need to find a carb. I'm stuck between a couple options. I thought of the truck avenger carb but...I just cant see that much $$$ for that carb in a way. So I'm thinking of a 625cfm Road Demon. Think that would work good? How should it be for offroad? Also what might I expect power wise from this combination. Anything else I should address?

 

that cam would work find, you can use the sock springs with no trouble, a 390 with a 4 barrell, headers and a mild port job, can give some pretty good hp and torque, it should work good for off-roading with no problem.

 

If you want a nasty lope and good low end power you need to get a cam with about a 108 Lobe Displacement Angle and around 225 degrees of duration. Don't mess too much with the intake as it flows pretty good in stock form. THe exhaust port is where you need to focus on. You can use 1.65 valves there also. The cam you are looking at will be great like fordman said but it will not idle rough at all. Your carb choice is probably as wise as you can get.

 

Will that provide a very noticable idle at all? I've not heard a cam around that size in a vehicle before as most ppl dont modify motors were I live.

 

i dont think you would notice much difference in the idle, ive got a ? about my cam crane 941 cam, will i notice any difference in the idle, and also what is the proper break in for a cam, ive heard run it at 2,000 for a while but i want to make sure as my project is getting closer.

 

Just a heads up in case you haven't bought the cam yet. It sounds like you are looking at a Crane cam from Summit ( buy the cam and get the lifters FREE! ). You can buy the same cam from Northern Auto Parts for $99.00, I called them this week about a simular cam and was told this was there everyday price and it also included lifters. Now, what to spend the extra $30.00 on......... Al

 

I'll check up on that thanks!

 

The 941 cam should lope a little but not too much. My 801 doesn't have a real nasty lope to it. Overlap makes an engine lope and with the wide lobe centers on the 801 and 941 it makes them idle a little better than the tighter LCA cams. There are a few guys here who run the 941 and could better answer the question.

Oil manufacturers quit putting zinc in their base oils. Zinc is good for breaking a cam in. You should run either valvoline racing oil or find a break in additive that contains zinc. I start the engine up and slowly take it from 1500 - 2500 - 1500 and so on for 30 minutes. You gotta be prepared to keep it cool as a new engine doesn't like setting in one place with the RPMs up. For more info on what to use for your break in lube check out www.lazercams.com. They have the whole scoop.

 

To make a correction to my first post where I said 225 degrees of duration:

That is at .050 but what really should be looked at is advertised duration. 275 degrees is probably where you will see some good loping if the lobe centers are tight.

 

If you are going to all the trouble of installing a cam...why not take a little time and consider the following...

Install New: cam, lifters, pushrods, valve springs (no need to remove heads from block for install), and timing chain.

Keep in mind that pushrods should "NEVER" be re-used with new lifters. And lifters should "NEVER" be re-used with a new cam. That should also include the "stock" timing chain .vs a good-excellent True-Rolling double Timing Chain. If possible...try purchasing a kit. These have been tested to work best together and takes away any guess work with matching different parts.

If you do decide to keep the "stock" valve springs...I would recommend testing each one and making sure it is within spec.

With engine out...these parts are a breeze to install.

Good luck with it!

 

I'm running that cam he listed in my 68 Merc's 390.It is the Crane 272 degree Energizer. It pretty much idles like a stocker once the motor warms up. It's got good bottom end and power up to around 5500 rpms. With a 10.5 to 1 comp ratio, it runs fine on 87-89 octane gas. I also reused the stock valve springs, and the original used pushrods for this motor. Been running a year now without problems. Nothing wrong with reusing pushrods, just as long as they've been inspected and have no abnormal wear and aren't bent, been doing this for years.

 

Iron Heads? What is your total timing? Thats pretty good.

 

You will be happy with a Barry Grant Carb. I have had the 695 Road Demon and 750 Speed demon on my moderate 390. Both have been wonder carbs that don't require much fiddling. The main diferance in the two will depend on the cam you pick and other factors as you know. Check out this link when choosing a Demon Carb...
http://www.truckpulls.com/Carbs_How_Big_Is_Too_Big.htm

 

Don't know what the total timing is. The initial setting is 12 degrees BTDC, the distributor is the original one that came with the car, stock single point single advance, equipped with a Pertronix unit. Pistons are the original cast flattops, heads are C8AE-H and have been de-burred, chambers smoothed a little. With the stock cam the motor would ping it's *** off.