Choosing a cam for Efi 408 magnum engine

[joegcuda68]

Hello,
I have a 1989 Dodge Dakota Shelby. This truck came with a fuel injection system. I plan on swapping the original 318, with a completely rebuilt 360 magnum stroked to a 408. Right now I’m getting ready to build the short block, and I’m wondering if I want to put an efi system or carb on it. This will change or effect the cam I put in it. I have cast cylinder heads, they’re decent flowing but not the best. I don’t know the exact ccs. I want a pretty rowdy cam, for sound but also performance. I want a hydraulic roller but I don’t know the specs I would want. I would like to run an efi system because it’ll probably be easier since I do not know how to tune a carb. What kind of cam would you recommend and why?
Joey

 

[dusterbing the peace]

I run a solid, flat 246/260 @ 050 on 112 straight up with the sniper efi (dual quad) on a 030 over 360. The system allows for quite a bit of tuning flexibility, just need a laptop and time to watch YouTube videos on tuning it. Steep learning curve is all. Lots of good info on the sniper forums as well. Oh, and definitely run a locked out distributor and let the sniper control the timing. Last but not least, get a converter that’ll allow you to run the “gnarly” cam. Mine thumps hard idling at 1,000 and about 14.5 AFR.

One of the biggest things you’ll want to get comfortable with is the acceleration enrichment (AE) vs TPS rate of change so you don’t lean bog when hammering the the throttle. This was probably the slowest part of the system’s built in “learning”, so I helped it (after reading enough about it to help myself). Can’t speak to other systems out there. Good luck and have fun!

 

[Tsully]

I run a solid, flat 246/260 @ 050 on 112 straight up with the sniper efi (dual quad) on a 030 over 360. The system allows for quite a bit of tuning flexibility, just need a laptop and time to watch YouTube videos on tuning it. Steep learning curve is all. Lots of good info on the sniper forums as well. Oh, and definitely run a locked out distributor and let the sniper control the timing. Last but not least, get a converter that’ll allow you to run the “gnarly” cam. Mine thumps hard idling at 1,000 and about 14.5 AFR.

One of the biggest things you’ll want to get comfortable with is the acceleration enrichment (AE) vs TPS rate of change so you don’t lean bog when hammering the the throttle. This was probably the slowest part of the system’s built in “learning”, so I helped it (after reading enough about it to help myself). Can’t speak to other systems out there. Good luck and have fun!

Are you still running the factory AC and PS?
Just curious on how the Vacuum was on that cam, I’m thinking with a 112, it probably has pretty decent vacuum!

 

[George Jets]

Hello,
I have a 1989 Dodge Dakota Shelby. This truck came with a fuel injection system. I plan on swapping the original 318, with a completely rebuilt 360 magnum stroked to a 408. Right now I’m getting ready to build the short block, and I’m wondering if I want to put an efi system or carb on it. This will change or effect the cam I put in it. I have cast cylinder heads, they’re decent flowing but not the best. I don’t know the exact ccs. I want a pretty rowdy cam, for sound but also performance. I want a hydraulic roller but I don’t know the specs I would want. I would like to run an efi system because it’ll probably be easier since I do not know how to tune a carb. What kind of cam would you recommend and why?
Joey

You would be surprised that your '89 318 factory Roller cam does quite well when you add a 1406 Edelbrock Carb to it.

Did this and it ran nice in my truck, lots of fun playing with the secondaries of the 4 bbl as you drive, keeps on pulling through the whole rpm range. Did not have to swap out the cam and roller lifters, all was good.

Manual fuel pump conversion adapter. ^^^

Give it the fuel it needs with that mid-rise factory port matched tbi intake, and set it up with the 4 bbl.

1406 Edelbrock

 

[dusterbing the peace]

Are you still running the factory AC and PS?
Just curious on how the Vacuum was on that cam, I’m thinking with a 112, it probably has pretty decent vacuum!

It does have good vacuum for what it is (13”), but again, idle is 1,000 rpm. It’ll idle down to 750-800 without issue, but with the solid flat I keep it a little higher. Only accessory is the alternator (electric water pump) out of a late 80’s truck to run fan, fuel pump, efi, etc.

 

[OldmanRick]

Welcome to the site Joey.

I'm old school, so i always consider budget on a question like this.

I've seen & heard some FI Chevy LS engines that sounded very radical, but they had some expensive Inj & timing systems to get them right. That 408 will make plenty of power for a nice street truck with a carb and without all the $$$ involved. As far as tuning, you can easily learn the basic carb stuff.

All that said, a carb with a 230/240@.050 roller with a 110ish lsa will give you big torque and the sound you're looking for. As far as the FI, i'll defer to the more experienced members.