I am rebuilding the motor in my 86 f150 this summer and am looking at supercharging it. I am building it for low end torque. The cam i have chosen according to compcams camquest is 31-255-5. This cam appears to work with the vortech supercharger i am looking at. Also using camquest i had noticed that my stock intake manifold is more beneficial than the edelbrock performer truck intake when comparing low end torque numbers. Im also going to put headers on it with am thinking ill be needing 2.5 dual exhaust since ill be putting the supercharger on. The boost will be 8psi.

Now i need your advice on which heads to choose. From what i have read the heads that are already on this truck work really nice but how would they be when adding the forced induction? Also would I keep my stock intake or should i upgrade to the eddie?

 

With forced induction the heads and intake don't matter as much because they will flow more air under pressure anyway, but there's always room for improvement. The truck intake is plenty big for just about anything you could want from a 5.0 but the dual throttlebody presents a plumbing problem for forced induction. If you substitute another intake get a car style with a single TB, the Eddie Performer falls in this category but so does the Explorer intake which you could probably get cheaper. There's also the Professional Products Typhoon which is an Eddie copy and it is probably the least expensive new intake you can buy. The exterior finish isn't as spiffy as the more expensive intakes but it's machine work is good so it'll will do the job just fine. Porting is always a good idea with the stock heads.. particularly on the exhaust, have these completely worked and opened up as much as possible. You should also clean up the combustion chambers and shave off the sharp edges around them, this will lower detonation sensitivity. If you want this motor to last you should invest in forged pistons and I-beam rods, a blown motor has to sustain a lot more stress than a NA motor and these parts will suffer most of that extra load. Forged pistons stand up better to mild detonation and you are guaranteed to get some of this with a 5.0 in a truck, the upgraded rods won't cost much more than it will to have ARP bolts installed in you stock rods, and they usually come with these bolts. You'll also want a boost control ignition system to help tame some of that pre ignition.

A good friend of mine had a blown 5.0 in his Stang, that motor made about 350hp and loads more TQ, that was essentially a stock HO motor though it did have some intake and exhaust upgrades.

 

Here is the link to the kit im thinking of getting.

Vortech 4FE218-078SQ - Vortech Centrifugal Supercharger Kits - summitracing.com


I dont think this kit has the controller but not sure.

 

I believe it does have the ignition system I talked about, the Lightning version uses a Crane box and the others use a Vortech box. This is a very comprehensive kit and even has a Y adapter for the dual TB on the truck intake, they thought of it all.

 

The stock heads will work, if anything, upgrade the valve springs to something stiffer with your application. Otherwise, a head upgrade will make a big difference as per seat-of-the-pants dyno. A couple of other things to look into is a fuel pressure gauge and a wideband O2; maintaining the fuel pressure is important and watching the A/F ratios is helpful when you dial in the FMU. You can also leave the wideband installed for continuous A/F monitoring while driving. At 8psi, I'd be afraid that the fuel pressure might fall off a bit with the Vortech pump and a if it does, you'll see the FP fall at the gauge and A/F ratios on the wideband will rise. You can go with a dual tank trigger and/or install a larger inline to take care of the lack of fuel; 190lph or 255lph should drop right in place of the Vortech pump.
I'd be a good idea to go with a spark plug that is one heat range colder than stock and close the gap to .035. This will help keep the combustion temps from getting out of control and causing detonation. The closer gap will keep from blowing the spark out under boost.