What would I do to build my 460 for low end torque and better gas mileage? Iv been thinkin of some aluminum heads and a new intake/carb set up. Im just not sure where to go for low end torque and possible gas milage increase. Im already hopin for a ZF5speed for the lower rpms.

 

The bigger the stroke the lower the peak TQ is in the RPM range.

Aluminum heads with bigger ports will raise the RPM range, helping power but hurting low RPM tq and mpg.

I'd clean up a set of stock heads, gasket match and blend the bowls some. Buy the biggest stroke crank as you feel comfortable with. Add a dual plane intake, headers and a small cam. (it depends on the size of the motor) In the area of 210-218 on a 114 for a 460ish motor, to 220-228 ish for a 500+ ci motor. That will make a TQ monster that will be a blast to daily drive, and when your foot stays out of it good MPG too.

High rpms make power but they're not as much fun as a TQ monster when you drive it to work everyday.

Just my .02

 

Iv heard its alot of work to machine out these old iron heads with the small exhaust port.

 

That's just it, with a low RPM motor you don't need large ports. Smaller ports, cleaned up, will still work well and make TQ.

The difference in the int to ex head flow can be helped out with the split duration cam.

If money isn't an object, by all means go with aluminum heads, but the power and tq range will move higher.

You wanted mpg and low end power, spend your money in the short block first, the heads can be swapped later if needed.

 

So I start with a longer stroke, rompier cam. What is a split duration cam exactly? I dont remember the term(probably herd it just dont remember). Polish the heads and dual plain intake. Moneys not much of an issue due to a future deployment, and Im goin to start a frame off resto when Im back.

 

You are not getting it yet. No rompy cams. You need a very mild cam, small ports in the heads, small dual plane intake(stock intake would work) small 600 cfm vacuum secondary carb, long tube headers and free flow exhaust, and a overdrive transmission you mentioned.

For fuel mileage with this engine you want it barely turning any rpms while driving it. For it to run correctly like this everything has to be small.

 

That doesnt make sense. Normally to get more power you need more air and fuel and compress them into a tighter space. To go small you dont get any of that.

 

You need displacement and port velocity.
The two go hand in hand.
Stroker crank = more displacement & compression.
Stock sized ports = high velocity at lower RPM's. If the ports get larger the efficient portion of the powerband is raised as well.

Oh, and get a straight up timing set in it right away. That right there will make a HUGE difference in how well it pulls.

 

Going with a big cam will increase the torque, but it will move it up in the RPM range. Which isn't good for low rpm cruising.

 

Ok so stroker crank, non-variable timin and a dual plain intake. Now am I seein it right? I never even herd of port velocity havin any thing to do with low end torque. And one last thing I want to remove alot or all of the emissions, so I need a new carb right? What size carb should I look for?

 

Not Non variable timing, non-retarded timing.
By getting rid of the -4* (-8* at the crank) timing that Ford used for emissions starting in the early 1970's you will see a lot more apparent torque.

Port velocity affects cylinder filling.
Tuned race engines can get to 120% of their static displacement.
But you need a cam to work with it....

I would recommend an Edelbrock 'Performe'r intake, the Weiand 'Stealth' has ports that are too big for low RPM's


600 CFM is just fine for what you want to do, in FACT the 4180 has annular boosters that are a very good feature. They atomize better than any other.
The only shortcoming of the OEM carb is it's lack of adjustability.

 

Ok so my factory carb will run with no emissions add-ons? Then really my truck needs very little to torque it up. Id start with a full tear down, new stroker crank, non-retarded timin set, cam, intake manifold, long tube headers, polish the heads and free up the emissions crap in the process.

 

That's a good start, it really depends what you're trying to accomplish.
The carburetor is really not "Bad" it just needs to be made adjustable. You can find info at the notchback mustang site Flemworld.com
A baseline dyno run would at least give you an idea where you're at now.
Recurving your distributor would be important as well.
Decking the block to get an effective quench would depend on what pistons you go with.

Porting can be done professionally or DIY. Depends what your time is worth and how proficient you are.

You might look at the Rein-carnation website. there's a lot of good information there.

 

Sweet thanks. My intentions are to upgrade my suspension/drivetrain to 350 and get more low end so that I can haul a large load for long distances with little effort and improved fuel economy. I expect to have to move multiple times in the next 6 years and my truck is goin to be the work horse.

 

An unexpected benefit of building a torque based motor is due to the lower RPMs needed you get a longer (normally) lifespan.