I have a 78 F-150 trailer special.
It has a 351m and not totally sure is rear diff a 9"?
Is tranny a C-6?
I wanna strip this truck down and put a 460 in it , which brings up more questions. I wanna do this on a budget of around $5k, but wanna have around 600 HP is this doable? Basically wanna build a street roddish drag truck.

 

Pics might help identify...

 

$5K is doable but what does it need versus what you want to do with it? And how wrenchworthy are ya? A scrapper?

Outside labor is a budget slayer so the more resourceful and more you can do on your own the better.

A rebuilt 400HP 460 is very doable with port-matched stock heads, a cam, 4V intake and 750 cfm carb, and headers/dual exhaust. But you're at $2500 to $3000 right there in machine work, a rebuild, and aforementioned performance-oriented upgrades as new parts. However, swap meets, bartering, and Craiglist can be your friend.

600 HP is gonna require aftermarket heads and a better valve train... PERIOD. Ya better rethink your budget.. like add to it.

We haven't even broached the subject of suspension mods... Oy.

 

Yeah, the budget is probably a bit low, I can turn wrenches, just suck at tuning but I know a guy I can barter with for that part. I am trying to look at all the batter ,trade, and other options. I am a gun dealer so trading can be done fairly easily. I do need to need to think about suspension. Probably will end up doubling the budget

 

Take off as much weight from the front end as possible, build a set of ladder bars and if you can, shorten the box and frame in front of the rear axle. A hundred pounds off will get you a tenth of a second. Use a shackle mount system on the front of your ladder bars, it's a pita to set up but it's better than breaking mounting points on the street. Theres a lot of ways to make the truck lighter, just how far do you want or are willing to go.

 

This should be a fun project , I probably won't shorten the bed, but other ideas sound good, gonna pull it to where I can get pics this weekend, its been sitting for a few years I will get the spider webs out I know the front end needs redone and actually may just find a carb and manifold for the current motor for now while finding all the new motor parts, if it was a crew cab I would just make it a tow rig. Still looking for a good crew cab for that purpose. As it sitss now, I know its gonna be flat black and a big motor and so far that's it.

 

With the budget and my impression of the goals I'd take a slightly different track.

Of course 400HP is rather easy, as much as 500 with more work, money, and loss of drivability. A legit 600 is a stretch, big bucks or loss of drivability, etc. But a legit 450 area plus nitrous for fun time is a very reasonable and practical way to get a driveable 600.

Save some bucks and keep it simple by doing a manual valve body C6, fun to drive with the right shifter and if the cam isn't radical an extreme torque converter isn't needed.

Save bucks by skipping building up a 9" and just swap in used 8 lug stuff front and rear, getting bigger brakes to boot.

4 link stuff is cool but a torque arm is cheap, easy and get's the job done.

If you want the flat black to look good without A LOT of ongoing work use a wrap not paint.

 

Thanks, that makes a lot of sense, I didn't think about drivability was just thinking more power.

 

Your welcome, a little more detail.

A vast majority of the engine cost and performance will be dictated by four things.

Head and cam choice these are a pair like peanut butter and chocolate, you can only use so much cam without aftermarket or modified heads. I "big" cam doesn't necessarily mean bad drivability, a high lift roller is likely an ideal of both power and drivability, but a pricey way to go.

Engine source, build from a core, buy a crate, or find a good used.

Displacement, IIRC kits can be had to take a 460 all the way up to 604CI. There's no replacement for displacement, 600CI makes 600HP much easier but that 600CI is pricey.

EFI or carb, you can get more drivability and power out of the same engine and/or get away with more cam with EFI but again, it's a cost.

All in all what I get the impression you want is HP that is enough to overpower the tires on demand at any point. But otherwise is fun to drive, sounds good, and looks cool. You can't do much of what I listed above with anything close to the budget you mentioned. You could however get lucky if you shop like crazy for a deal on a used engine. Pull it apart at least down to a short block, go through the heads(port match), measure(CR is key) etc. and maybe put in a better cam. If it didn't come with them install dual quads then a great exhaust and a good nitrous system. FWIW nitrous in and of itself is cool

 

What will the primary purpose of the truck be --street use or track use?

Street vehicles don't make good track vehicles and track vehicles don't make good street vehicles.

High horsepower requires proportionately more fuel to run. If the engine has high compression (to make 600 hp, I presume it will be a high compression engine), will require more expensive pump gas and more often.

Depending on the lift/lobe separation of the cam to be used and depending on if you have a vacuum brake booster, the booster may become useless, due to a lack of vacuum from the engine. You'll need at least 18"-20" inches of vacuum from the engine for the booster to work properly. Going from power brakes to manual is going backwards to me. The only other choice, to keep power brakes, would be to swap in a hydroboost brake unit that's run off the power steering pump.

This brings up another potential problem; if the suspension has stock, worn, bushings, kingpins, tie rods, steering linkage, gear box and deficient brake components, the going fast is going to be fun --up to the point you go to put the brakes on.

If the truck is all over the place and the brakes don't work so well, all the go fast suddenly won't be so much fun.

Lots of things to consider and areas of the truck that will have to be addressed/beefed up first to handle that sort of horsepower. $$$