Next summer I hope to begin stocking up parts to build my '78 400 engine. Im looking to have it make roughly 400 horsepower and have decent low end torque. It will be going in my daily driver...my '78 F250 supercab with the C6 (that will be rebuilt to stock specs) and with 4.10 gears. Im also hoping to obtain a slightly more lopey idle. I plan to put on an edelbrock dual plane manifold with around a 650-750 cfm carb. My compression Im hoping to have around 9.1:1 because Id like to still use pump gas. The truck with retain its dual exhaust with the stock exhaust manifolds as well. Namely what im looking for at the moment is what cam to toss in there. I found this one, but Im not sure if its the best one for my application judging by its RPM ranges. What cams/setups do you guys have in your trucks? I plan to keep my truck as a daily driver that is capable of towing when I have to. I dont need a drag truck, but I would like to get some more acceleration/torque out of it.

One more thing I plan to keep the 4.10 gears as well if that matters.

 

400 hp will be tough with exhaust manifolds. A set of Tmeyerinc Keith Black pistons to get the compression up is a must, if you want the HP and are willing to part with the dough a Custom Hydraulic roller cam will get you closer to your goal. A set of Howard's linkbar lifters will make it work in your block. Do some reading in the 335/Cleveland engine section for more info.

A build identical to mine made about 350hp and about 450 ft-lbs. on an engine dyno

(Aussie Cleveland heads and a comp XE 262)

do some reading on www.tmeyerinc.com

 

I agree it's going to be tough with stock manifolds. I built mine a year ago with this cam:

32-237-4 - Magnum

I'm very happy with it. Not very lopey, but tons of torque and good HP. I have not had her dyno'ed yet, but I'm thinking I'm around 350hp and 400 torque. However, I put in a new crank, timing gear, flat top pistons, have long tube headers, Weiand Stealth intake, Edelbrock 600cfm, etc. I put a pretty penny in to parts. Doing it over, I'm not sure if I would change the cam since I'm so happy with it. I may be interested in some CHI or Aussie heads just for kicks.

Let us know what you decide to go with.

 

@ brokersteve: thats the cam I was considering. I like the idea of the bottom end torque BUT...Id like a lopey idle. I don't need the truck to sound like a drag car but Im looking for something that sounds a bit more agressive than stock.

Overall 400 hp was just a guesstimate of where Id like power figures to be. 350 hp would be plenty...especially if its got 400 ft/lbs torque. I plan to add a double roller timing set, a new stock factory crank, flat top pistons, probably an edelbrock performer 400 manifold and a holley double pumper 650 cfm carb. Do headers really make that big of a difference when trying to up horsepower? Ive always been told that they boost it minimally...very minimally.

 

Keep posting what you find out. I'm going down the same road with mine. Looking to rebuild my 400. I want to use mine as a daily driver, but also have enough HP/torque to tow my 18' car hauler and use regular pump gas.

 

I know I also plan to get it bored .040" over. Not sure what I'll do with the heads just yet besides rebuilt them. Also not sure what I should do for rockers...I've been thinking about roller rockers.

Additional stuff for the build includes a lot of "commonplace" stuff but is kinda as follows: high volume oil pump, HEI distributor, MSD ignition, MSD plug wires and I "think" stock spark plugs. To deal with cooling I want to put in the electric fans out of a Mark VIII and a new Super Cooling radiator.

 

As far as cooling, if you have any doubt about the Mark VIII fan being enough (it's a single fan), it does a great job of keeping the big idi cool. Take caution if any light weight people are near the front of the truck when the fan is on as they may be sucked up against the grille lol. I'm running a 3 row aluminum radiator for a 351 so I would think something like that would be good for you.

Sounds like a cool build though, are you going to restore the rest of the truck or just keep it as is?

 

Brokersteve - I'd bet you're well above 400lbs.ft. With that cam, at least if the rest of the build is pretty typical.

Dave145 - headers are almost a must with a real performance build. I think it was Hot Rod that did a nice 406 build up and got just over 380 HP, but they spent 16 hours porting just the exhaust manifolds. The heads had a fair amount of work too.

I'd bet headers are worth at least 30 HP over stock manifolds - at least. It won't turn a 150HP dog into a world beater, but I think 30+ HP is substantial. Good idea on the double roller timing chain set... A must have IMO. There is some concern with a HV pump that you can pump the pan dry - so be aware of that.

 

Hmm cool info on the headers. As for the oil system, id like to toss on a larger pan...maybe an 8 quart if there is such a thing?

I'm not sure if the truck will be restored or what right now. It needs a new cab because the mounts are rotted through and the bed sides are mostly that epoxy resin. It might be but I'll have to see how broke I am when I finish building the drive train!

 

I know she pulls really strong. I start in second of course, but have no problem spinning loose after shifting in to third at 40. On mud tires, LOL.

I do want to get her dyno'ed. I just have to work out a few kinks with the carb. She starves a bit at WOT which hurts performance.

I also tow some with no problems. Not too heavy. Loaded 12' landscape trailer, etc. Of course fuel economy is another story. The new 38 gallon tank helps to keep from stopping so often...

 

Brokersteve,

It takes a lot of torque to spin tires at that speed. You're probably making 450lbs.ft. Or more torque, HP I'm not sure, but the 600CFM Edelbrock carb might be a bit on the small side.

 

From everything I've read on this forum, the 600CFM should be enough, but a local race car builder checked it out for me and he said it acted as though it was getting too much air and not enough fuel at WOT and I needed a bigger carb. I am not sure if rejetting would help or not. Have not gotten around to changing the jets yet.

Sorry, didn't mean to highjack the thread.

 

I strongly suggest headers, because the cast iron manifolds tend to crack and they cost as much as the $149 Flow-Tech headers that I replaced them with.
They are probably good for 20+hp, in a 351M/400, but only if you provide induction upgrades.

Don't have any real "back me up" numbers, but "seat-of-the-pants" experience tells me the 351M F-150 4x4 hunting truck, carrying a 400# dog box and 500# of dogs, is in the ~300hp range with tons of torque.

Mods:
Edelbrock Perf 400 (think Weiand 8010 Action +Plus is perhaps better choice)
Edelbrock #1826, 650cfm, Thunder AVS (w/#1842 Thunder AVS Carburetor Calibration Kit, calibrated 2 stages leaner to #1806 specs)
A 2" 4 hole carb spacer (looks odd, but noticeable torque/throttle response in the 500-2000rpm range)
Crane Cams 278 H10 grind, advanced 4* (shifts torque/hp curve ~500-700rpm lower)
And this is without a C/R increase. If bumped up to ~9.5, with the Aussi 2V heads, it should increase the HP close to ~330-340.

Oil pressure on this 200K mi motor, is down to ~30# hot at 2000 and 5-10 at idle, so a rebuild is lurking around the corner, but will try the oil feed around to the rear first. It will be a cheap mod to see just how much the rear oil feed really helps.

Hope this is of some help to you.

 

oil feed around to the rear? I think Ive heard of that but I have no idea how that works.

Im VERY new to rebuilding engines right now. I have plenty of mechanical know-how and I have plenty of tools to do the job, but right now Im still kinda educating myself on how to do this and get good results out of it.

@51fordf5: I have some interesting ideas for the truck. It's going to undergo a sort of "restomod". Entire driveline will be built to mild performance specs, disc brakes in the rear, new suspension, 3G alternator, retrosound radio and a quality audio system, dual battery setup, new wiring harnesses, redone AC, added courtesy lights, etc. Mainly its going to look the same but its going to get a lot of things to make it semi comparable to what most modern trucks have. Yes, cruise control will be added (factory cruise control if I can find a system). And yes, I will be keeping the manual windows and locks

 

That's cool man, I've got a 3G alternator waiting to go on mine. You should drop that thing lol long and low. When I first got the truck, there was a single cable going over to the driver's side that looked like there was another battery at one point. I just took that off, I didn't have money to spend on another battery. As to the cruise control, if I recall that truck has it on the turn signal stalk. It never worked, I think it just needs the servo and a bit of rewiring. Don't forget to look above the rear driver's side vent window because it was getting rusty when I had it and I doubt the owner(s) after me and before you did anything about it. I would hate for you to get done with everything and then have that rust out up there