I'm a newb to engine building, but I've been doing my homework and I have a few questions. I have a 94 Bronco with a 351w. I'm in the process of "improving" it a little. What I'm looking for (what every good Bronco owner is looking for) is more power without losing street behavior or off-road usefulness. Obviously torque is the primary objective (low and steady).

Mods so far include full length headers and true dual exhaust.

I've bought some GT40 heads and a stock lightning cam and computer. I was thinking about putting these on which should give me the rough equivalent of a lightning top end.

That said, I've also been reading up on the Comp Cams Xtreme 4X4 which seems like it might be a better choice given the fact that I'm not interested in bracket racing.

Any suggestions from some of you tricked out Bronco owners out there? Is the GT-40 head swap worth the trouble without going to a more aggressive cam?

Any info is appreciated.

KC

 

isn't the lightning supercharged? If so then the cam may not be the answer for a normally aspirated engine.

 

I should've be more clear. This is the cam from a Gen 1 Lightning.

I did a little figuring with desktop dyno and it seems that the Comp Cams Xtreme 4x4 makes about 10% more power(tourque) than the lightning given the same engine. Does that sound right?

 

As far as what you want out of a cam is reasonable. However, the XTREME 4x4 line of cams is NOT for E.F.I.. However, Comp Cams makes a cam for computer controlled engines with E.F.I.. The cam is for speed density e.f.i., and works with a stock computer. It features very strong torque, excellent mileage, and a good idle quality. The operating range is from 1000 to 5200 rpm's. The camshaft part number is 35-255-5. The camshaft grind number is XE254H. The duration @ .050 Intake 210, Exhaust 214. Valve lift w/1.6 rocker Intake .478, Exhaust .485. The lobe separation angle is 114 degrees.
So, if you have speed density set up, this would be an ideal cam. The GT 40 heads are ok, and the headers are icing on the cake.

 

Gracias Mako. I appreciate the info.

Looking at the lobe separation, that should've been a clue right?

 

actualy, if you have a maf setup, then lobe sep isnt as much of an issue, u can use 110 lobe sep but its risky i called comp cams and talked for like half hour about it.