Hi i'm new to this engine, so please help me with parts. I'm going to put it in my 1978 ford F-150 with a NP435 4 speed, with 3.50 gears and 33-35 inch tires. I was hoping for about 250 HP at 4000 RPM and 350 FT/LB at about 2000 RPM. Here is what I've come up with.

Turn crank .010 under
bore .040 over with 9:1 CR
port and polish the head and do a 30 degree valve job then 1.94 Intake and 1.60 exhaust valves
then a comp 260H cam k kit
Next a Offenhauser dual port intake
With a Holly 390cfm carb
top it off with a Headman 6 into 2 header.

Will this work and were can I find 9:1 piston?

 

I can't help you with the build, but others can, like AbandonedBronco or F250Restorer or Harte or about 15 other guys who have built these 300's into powerful, small-block-eating machines.

However I wanted to throw in my two cents; For tires that big you should consider lower gear ratios. Is this truck going to be a toy or a daily driver?

For 35 inch tires I would run 4.10's, especially with a built 300.

Is there anything else that you need to know about this engine?

 

It's going to be my daily driver,I would like to be able to drive it down the highway. What about 3.73, i'm shooting for 33" tires but 35" is just an option. Thanks for the input.

 

The Comp 260H will put peak torque at about 3000 rpm and hp at about 4500 rpm but the increase over stock is through the whole range from idle up. Federal Mogul or Silvolite hypereutetic pistons are suggested. The Silvolite site has many listed for the 240/300...or at least did at one time. Your compression goal might be easier met with head and block milling...check with an automotive machinist on that. Unless you plan on considerable tinkering to get the Holley dialed in, an Edelbrock 500 cfm might be the better option.

 

If I were you I wouldn't go any taller than 33 inches. That's all the tire you need. 3.73 would be fine for 33's. 4.10's for 35 inch tires. The 300 actually does best with higher gear ratios; however, tires that big warrent lower gears. Running 35 inch tires with 3.55 gears will underpower your truck enough to kill your fuel mileage.

If I would suggest anything, it would be 33's with 3.73's. I am running 31's with 4.11 and the truck has great low end torque but no highway power. The 300 with it's powerband and low end torque does best with higher gears, like I said, but 33 - 35 inch tires are pretty tall to turn over. You want the leverage that a lower gear gives you.

Pay attention to what Harte says. His F-1 is a beast.

 

I think I'll stick with 33" and 3.73. Do you guy's think I should run a Comp 252 cam to reach my desired power band. Thanks again.

 

arent stock pistons / heads ~8.5:1? find a 240 L6 head to build, p&p...with stock pistons should put you ~9.1-9.2:1 (from what i've read)...its also a better flowing head. Could also mill it for more compression.

 

Even with the 260H you will probably be closer to 210-225 hp. The only way you are going to find out where it ends up is with dyno runs after building it.

There are several pages here FORDSIX PERFORMANCE • View topic - FIGURES of computer projected HP and TQ for the 300 run on the Desktop Dyno program.

 

Thanks for the cam data, I think that i'll stick with the comp 260H cam. I found on kb-silvolite.com a set of pistons that will give me 8.7:1 compression, I figure that if I shave the head .020-.030 I should get about 9:1. Right? Thoughts on roller rockers.

 

Not knowing whether the head and block may have been already milled in the past, it's hard to say. A 240 head will give about a .5 bump in compression. There again, consult a machine shop on the milling. They can measure the block and head, cc the head and project what it will take to get you to your target CR.

And thanks Bill...but Flashy is the one with the ultimate beast

 

Sure, but other members have what I call "realistic builds", including you and Justin and several more. Flashy has a beast, sure, but most aren't going to be so radical in their 300 build. Besides that, Justin told me about getting to ride with you. He said in a blink of an eye you were going 80 mph, and still pushing hard.

Man, is it Friday yet? Sigh.

 

I'm still in the process of building my 300-6 i've got the motor, and torn down, now i'm working on the truck that i'm putting the morter in. I was worndering on thoughts of puting a turbo on my 300-6. How much more power, gas mileage,what type of turbo, intercooler,and,thoughts on zf 5 speed.

 

FORDSIX PERFORMANCE • View forum - Turbo, Supercharger, and Nitrous Start your turbo education there.

 

Ya know, though, if you look at what Col. Flashman did with his 300 it's not all that radical based on the specs:

https://www.ford-trucks.com/forums/3...ml#post2912007

300 H.P. @ 4600 rpm & 400 Torque @ 3200 rpm w/ a 10 to 1 C.R.
It idels @ 675 & is smooth as glass, a quarter was placed on top of the Valve Cover & it Did Not move Nor rattle @ least on the stand anyway.

Ross Pistons 4.060
Hastings Power Flex Rings .060
Federal Mogul Mains .020 Under
Clevite Performance Bearings Std.
Federal Mogul Cam Bearings Std.
Melling Torque Cam
Melling H.V. Oli Pump
Eagle H-beam Rods 6.300 2.100 Rod Journal
Crane Gold Race Roller rockers
ARP Main Stud Kit, Rocker Studs,
Fisher International Ballancer
Bore 4.060
Power Hone 4.060
Full P&P Intake & Exhaust
Performance valve job
Performance Balance job on Steele Crank w/ in 7 grams
Grind Rod Journals to 2.100
Plumb Intake for Heat via Water Pump
Deck Block to Square
Align hone to Factory specs
Deck block for Zero Deck
Offenhauser C Intake (thinking of going to a D/P)
Holley 1850 600 CFM
S.S. Borla 2 into 2 Header
8' of 3" tubes attached to Flowmaster 40's
4 Core Desert Radiator mated w/ the Original Radiator Housing
2 1,200 CPU Electric Fans, on @ 180*, off @ 170* mounted diaginally
MSD 6A Eclectronics Package & Coil
Mid 70's Ford Electronic Ignition (the mallory wouldn't fit?!.)

So the 10:1 forged pistons are a bit more than most folks would do. The crank was ground to add ~10 ci of stroke - which shouldn't make a huge difference. Premium balancer, S/S headers are pricey but aren't going to make a difference in performance. And he's running a beefy exhaust system.

Other than that it's pretty much standard performance machine work. That Melling cam is mild too - ~206 degrees duration at .050" IIRC. The only real variable is the head and how it flows.

I wouldn't mind seeing a chassis dyno follow-up for his combo either. It's hard to imagine a normally aspirated 300 (or 316) cranking out 400 lb/ft of torque with a relatively mild cam. Not calling anyone a liar, just seems a bit high.

It'd be nice to see dyno sheets from everyone who's hopped up their 300 for that matter. Maybe once the weather warms up a bit I'll get the ball rolling and cough up $100 for some dyno time to see what the Offy C and EFI manifolds bring to the party.

Anyway, a nice six doesn't have to break the bank. Just be realistic about your expectations.

 

Oh, and the ZF is a nice swap depending on what you're looking for. It's a truck tranny and it shifts like one. If you're thinking hot rod, think something else because it won't bang through the gears like a TKO-500.

It has a lugging rattle at low RPM, and if you use a cheap clutch set (ask me how I know...) it's noisy at idle in neutral.

With the granny 1st and OD 5th it's basically a three speed around town. That .76 OD gear is very nice on the highway.

The ZF is a crusher though. The only thing that usually goes south is the shift forks. Get it bench rebuilt if you buy a used one. Again, ask me how I know.