I bought a 1984 F250 4x4 with a 460/4spd. It is pretty much stock, accept for a cam with Duration 262/270, Lift .513/.520, a edelbrock vivtor intake, and edelbrock 750 carb. the rest is bone stock. motor was freshened up less than 300 miles ago. Im wondering what the horsepower range would be. thanks

 

My stock '85 460 is rated at 250 hp but I could not guess what yours is but.......................is it really that important to know how much hp it's making? Are you satisfied with the power now? Are you satisfied how it runs? If you are than it doesn't matter if it makes 50 or 500. HP ratings are just a number on a piece of paper.

 

I'm not going to guess at what HP range it might be in, I will mention tho, that with the rest being "bone stock" the intake on there is not helping out any. The victor is a single plane intake made for top end power, the cam (looks like a Comp Xtreme Energy XE262) is designed to start building power at 1300 rpm, compare that to the victor intake which starts around 3200-3500 rpm. Toss in the stock cr of 8:1ish and the parts are actually working against each other to try and make power. Even the carb is overkill as the mismatch between the intake and cam is actually going to hurt your volumetric efficiency. As a rule of thumb, you can figure around 80-85% VE for a mild build. Assuming a 83% VE, your motor only needs a 650cfm carb (618cfm calculated) at peak power (5600 rpm based on the cam). However, considering the mismatch of parts, I seriously doubt the previous owner took the time to port match the heads to the intake (from Edelbrock: Standard 429/460 cast iron heads will require port matching of the head to fit manifold. ). If thats the case, the mismatch on the ports will actually HURT your VE and drop it to around 75% or even less. Assuming a 70-75% VE your motor only needs a 570cfm carb (520-559cfm calculated) meaning that 750cfm carb is not helping you and actually working against you once again.

If you change over to a dual plane intake (Edelbrock Performer or Weiand Stealth) and a 650cfm vac secondary carb, I think you would be very surprised at the increase in usable power you would have.

 

Even just switching intakes and using that carb will help

Even tho the carb is bigger then you need, it's not really hurting you just not gaining so if you don't want to spend money right now you can leave that but definitly switch intakes. Switching carbs would just waste money IMHO.

Ward mentioned a couple but I woudl change that to performer RPM or Stealth with the stealth being first choice.

 

The Weiand Stealth is actually my first choice too. Comes in strong right off idle and flows well all the way to the redline (Weiand claims idle to 6800rpm operating range) with that intake on the 429, 11.5:1 cr and a Comp 278/288 cam (234/244 @ 050) it would spin 7000grand on the tach with no problems, and flat roast the tires (35" mud terrains, 3.55 gears and a c6) but still be cruise around friendly at the lower rpms too.