Building a 408w for towing

[BLstangin]

I just bought a 86 f150 short box standard cab. with a 351w ho and a c6 and 9" in it. It is in real nice shape but the motor overheats and uses antifreeze. I'd like to use this truck to pull my mustang to the track and general purpose truck use and also make a little hot rod out of it. I was thinking about putting together a 9.5:1 408 with afr 1458 205cc heads on it and a roller cam with a set of long tube headers and fitech go efi 600 efi. I was wondering what you guys think of this plan? I'd like to use all the stock stuff including valve covers so it looks like a stock 5.8 HO. Even has a/c and cruise and I would like to retain all of that. Wondering what intake I should use and what size cam I should put in it. Has to be able to tow a car trailer and be able to hot rod around town. Thinking around 6000-6500 rpm max. Should I use something like a rpm air gap intake or will a single plane work ok on it? Any and all suggestions welcome as I haven't bought any parts yet and want a refined plan for power and drivability before I start. It must be able to be daily driven on pump gas also.

[wyrmrider]

I laying out a couple of similar so will be lurking
just off the cuff
heads too big?
cr to high for iron heads someone can chime in for aluminum
not the stock FI?
what gears?
I'm thinking of swapping the C6 in my 4x4 83 bronco with an AOD when I replace the tired 302 with a 351 or 408- it's geared low for but would be perfect with OD

[Carnut1]

Check out my Build a Lightning Bronco? Thread.

[BLstangin]

I plan to use aluminum heads on this one and the 86 with a 5.8 HO is carb not efi and I would like to go efi so that's why I was thinking fitech, simple self tuning and cheap. I currently have no idea what gear is in it but it is a 9" so I can change ratios pretty easy. I was thinking down the road a 4.10 with a aod swap but we will see what happens first I need it to run!

[peejay]

I personally wouldn't want to run an aluminum head in any small block Ford that was going to see towing duty... there's just not a lot of room for cooling jacket in the head once you replace the thin iron with thick aluminum, and something you need for towing is COOLING since you're running at a higher HP level for hours, not seconds at a time.

99% of aluminum heads are made for people who want to make power for seconds at a time, if you're towing you need to be able to bolt the throttle down for minutes at a time and settle down to a mild bellow for hours...

[KnightEngines]

How about a clevor/boss type engine, with some of the CHI 185cc 3V heads? - similar all up cost with those lovely Cleveland style heads.

[Walter R. Malik]

Those heads are way to big for towing.
I would use a 393 cubic inch engine with Ford Racing M-6049-X306 heads with a 1.7/1 rocker arm if gas mileage and highway torque are any priority at all.

That truck family was available with both EFI and a Carburetor depending upon what state it was originally sold in.

Using a "marine" flat tappet camshaft E7JE-6250-AA, (or something comparable), with a 1/2" PHENOLIC intake manifold spacer and an adjustable fuel pressure regulator to raise fuel pressure 10% or so, and you can even use the O.E.M. Fuel injection.

With a carb, you can do almost anything. Use the same type camshaft with an Air Gap intake manifold and the 4180 carb which came on it with a lighter secondary spring and no check ball.

This will get you an economical 400 horsepower and over 400 LB/FT of torque.
Been there, in both cases.

[Walter R. Malik]

Those heads are way to big for towing.
I would use a 393 cubic inch engine with Ford Racing M-6049-X306 heads with a 1.7/1 rocker arm if gas mileage and highway torque are any priority at all.

That truck family was available with both EFI and a Carburetor depending upon what state it was originally sold in.

Using a "marine" flat tappet camshaft E7JE-6250-AA, (or something comparable), with a 1/2" PHENOLIC intake manifold spacer and an adjustable fuel pressure regulator to raise fuel pressure 10% or so, and you can even use the O.E.M. Fuel injection.

With a carb, you can do almost anything. Use the same type camshaft with an Air Gap intake manifold and the 4180 carb which came on it with a lighter secondary spring and no check ball.

This will get you an economical 400 horsepower and over 400 LB/FT of torque.
Been there, in both cases.

I just went and looked it up ... ELGIN sells a replacement to that camshaft as Part Number E-870-S
206/221@.050" - .278"/.283" cam lobe lift - 115 separation; 116 intake lobe centerline.

A cam having a bit more lift and slightly tighter separation with earlier intake centerline can be used with a carb for getting a little more torque but, not with factory "speed density" EFI.

[induction apprentice]

Heads are to big, compression to high.
remove compression, add cubes.

[TTXPC]

apples to oranges but... for my tow rig I built a 302 with dart pro1 heads, small hyd flat tappet,hyper flat tops mid 8's comp, non intercooled s400 turbo on propane 12 psi. puts down 340rwhp, topping out the E convertor. In a 5000lb tray truck.
doesn't get hot, does everything I ask of it fwiw

[BLstangin]

Interesting that you guys think its to much cylinder head and compression I thought I was being conservative actually. I do also have a set of factory D0oe heads that have some mild port work with stainless valves, hydraulic roller springs, screw in studs and guideplates already on them that came off the 302 in my mustang years ago that I could use. They only had 500 ish miles on them when I pulled them off. What is a safe compression ratio? I want to be able to pull stuff with it but I also want it to have a little bit of a choppy idle and make some decent power. The reason I was looking at the afr head is because I can get my hands on a brand new set for $1300 bux.

[BLstangin]

Also I do NOT have the factory efi on the truck and don't plan to add it when I can put the self learing fitech on it for around $1200 bux with their fuel system. Just seems so much easier than trying to make a factory setup work and wiring it all in.

[jeff swisher]

I had a friend that had the same truck it was extended cab long bed with 351HO and holley carb from factory.
C6 and the 9".
It would get 12 mpg factory.. I recurved the distributor and it got 14 mpg.

Another friend ended up with it and pulled the now knocking 351W from it and stuck in a 350 chevy and TH350..It ran soooo much quicker and pulled loads much better.

I think you are on the right track with using better heads.
I built a 306" for my 6000lb ford van 1982 engine and heads.. I ported the 2v intake and porthed the heads and ex manifolds and ran a 3" single exhaust system.. recurved the distributor and ran a bunch of different carbs. It had the AOD and 350 gears in a 9"..I could not use the OD as the little engine would not pull the weight at low R's . I used a comp 260H cam. It was good for 2 MPG over a stock cam that was advanced 4 degrees.
MPG was 17.6 city or highway with or without a trailer in tow. A couple times through the states on I40 it got more than 19 mpg.
I wished i used early 289 heads on it to get some more compression.

Depending on how crafty you are on prepping the combustion space you can get by with some good amounts of compression and run pump fuel.
But cubes are king when pulling stuff... That 306 still pulled way better than any 351W i had. I even took it to the track and it ran 18.0 in the 1/4 on a hot summer day.

I stuck many 455 and 403 oldsmobiles into chevy trucks that were used for roofing crews.. these trucks ran just as good empty as loaded.

I would pick a head with a small chamber .. as I have found the smaller chamber is less detonation prone than larger ones..If the shape is correct.

With my small block chevy I shoot for 10.4 minimum compression with iron heads and cams as small as the 268H I pull trailers most of the time and the added low speed TQ I get with the compression boost really makes a difference.
But my chambers are less than 64cc and all sharp edges are removed from chambers and pistons..Intake runners are roughed up from below the carburetor to the valve job with a hard stone..I want to keep the fuel atomized as much as possible..I still run carbs.

Of course I run 91 octane fuel also..You can run 87 if you keep your foot out of it.
Everything you do to this build needs to be thought out.
I have had some factory 400" fords and all had 2 barrels and ran super great..
Depending on runner length and flow the 200+cc heads may not be big to the engine.

I did one experiment with the pushrod pinch on a 350 chevy..One engine had the pinch pushed way back and a 268H comp cam on a 112LSA and the other had the pinch left as is NO opening of the intake port entrance and a 260H on a 112LSA .. thinking the smaller pinch and smaller runner and smaller cam would give better mpg.
It did not happen.. The head with the pinch opened up to 1.99" CSA and larger cam got better MPG same casting head #601 and same 1.84-1.50 valves same port work same vehicle etc etc.. tried to keep it as much apples to apples as i could.

What i figured is the fuel was not liking to turn corners..
So many things that will work well together change 1 or 2 little things and it's ruined.

Have fun.

[Keith Morganstein]

Interesting that you guys think its to much cylinder head and compression I thought I was being conservative actually. I do also have a set of factory D0oe heads that have some mild port work with stainless valves, hydraulic roller springs, screw in studs and guideplates already on them that came off the 302 in my mustang years ago that I could use. They only had 500 ish miles on them when I pulled them off. What is a safe compression ratio? I want to be able to pull stuff with it but I also want it to have a little bit of a choppy idle and make some decent power. The reason I was looking at the afr head is because I can get my hands on a brand new set for $1300 bux.

Really it depends on the amount & type of towing. When I think of a purpose built tow engine, I want peak torque at the rpm your pulling down to on hills.(where the engine has the best BSFC) Having peak torque at a lower RPM will save fuel.

If it's a hot rod truck that does a little towing and fuel economy isn't the consideration, bigger heads and cam might be what you want.

[BLstangin]

The truck will probably just be used to cruise to work and roll ins and just joy driving mainly but I think it would be cool if I could put my 70 mustang on a car trailer and tow it to the track a couple times a year so it needs to be able to do that. I'd like to put a aod in it and like a3.89 or 4.10 rear gear so that when I'm cruising I can let it run in od at 2000ish rpm at 60mph and when I have a trailer behind I could pull in 3rd and be in that 3000ish rpm range and I can always kick it down to pull a steep hill. It doesn't really need to turn over 6000 ish rpm though because I wanna use the factory 6000 rpm tach in the dash so it just looks all stock. and for a street truck I'd rather build it to make torque a little lower but I don't want it to be dead at 5000 rpm either.