While researching what cams will work in my '92 EFI 460 I've heard over and over that the Speed Density EFI hates overlap. So wide (112-114) lobe seperation angles and short duration are needed to minimize the overlap. I've narrowed my choices down to two cams, both pretty short duration, sorta high lift, 112 LSA cams. When looking at the cam grind specs, it looks to me like there is NO overlap on this grind (see link below)


Voodoo Hyd Cam - Ford 429-460 250/256 - Lunati Power

with the ex closing at -9.5 ATDC (or 9.5 BTDC..) and the in opening at -4.5 BTDC (or 4.5 ATDC, right?) it looks to me like this grind will have both valves shut (or open less than .050") for 14 deg, right? Or am I missing something??

Do you guys think this will be a SD EFI friendly cam?

 

I have the same truck except mine is a five speed. That cam should work good I have a Speed Pro cam in mine with 204/214 duration at .050 and
484 intake and 510 exhaust lift 112 lobe c/l and 51 overlap part # CS1086R.
It has been in there for 50,000 miles and works great. I also have a cold air intake, headers, bigger intake valves and 3" flowmaster exhaust. I have played with mine quite a bit so If you have any questions let me know.
Richard

 

Thanks for the info, I'll look into the SpeedPro cam. Have you made any changes to the computer? And do you have emissions testing in MT?

Great to hear that your combo is solid, with the exception of the bigger intake valves you have what I'm planning to build.

 

The computer is stock and I haven't had a problem. We do not have testing up here so I don't have any idea if it would pass
Richard

 

Great to hear that the computer is working for you, the speed density EFI has been my big worry. I'm liking the $ of the Speed Pro cam kits also, about $100 less than the Crane or Lunati stuff I've been looking at. One more question, are you running a Cat?

 

The cat and the air injection are gone the O2 sensor was bad when I bought the truck and the cat was melted inside and plugged so it went away. And then the air injection has no place to go so that was removed also.
Richard

 

How big of a chore was it to remove the air injecection? Did you have to mess with any sensors etc?

 

Here is another cam that will work for you. Crane #270-353902. I ran one in a 89 efi 4x4 crew cab with the e4od and 4.10 gears. the computer dosn't mindit however you will need to up the valve springs a bit and shim the rockers to set the lifter preload. all parts avalible from crane.
Lift: .487''/.518''
Duration: 260°/272°
RPM Range: 1200-4800
Put 60,000 plus on it before I sold the truck.

 

There was on mine a red vacuum line that ran from the valves on the passenger valve cover over to a valve on the driver side valve cover next to the coil this is the valve that runns the system.
I unplugged this line and capped the port on the valve. you then can remove everything and at least on mine the computer does not know its gone. you will need to run a shorter belt and cap the ports on the cat if you didn't remove it. As I said earlier my cat was plugged and so when I removed it there wasn't any place for the injection lines to go so I removed the injection also. When I bought this truck the mileage was terrible and it ran like a 6cyl
after I put the headers and 3" exhaust on it is a different truck and it gets 14 to 15 mpg on the highway.
Richard