I want to build a stroker for my 73 F-250 and I always hear of the 514, the 521, and the 545. I want a .030 overbore and I think a 4.3 inch stroke. but whats the power differences between the 4.13 stroke, the 4.3 stroke, and the 4.5 stroke? I want to go with a roller cam and roller lifters, roller rockers, and i want to build it to get the most power and milage out of the Propane conversion(is propane a good idea or not). I dont know about the heads though what would be better ported stockers of some kind or aftermarket heads and if so which are the best? i want to put a ranger overdrive behind with the NP435, but my goal is 600hp and at that range will the overdrive hold up to that? Advanced adapters says the unit will handle 420lb/ft of torque. I havent built anything yet but i would like to get a feel for what others of you guys have done. I want enough power to tow a 35 foot fifth wheel over Mt. Hood at 70mph and do it efficiently. This truck will tow a lot and be a recover and base camp 4x4. Please help anyway you can, all input is appreciated, what would you guys do?

 

A 75 mph run over a hill with a 35 foot trailer and good mileage????


Drop diesel in it? Really.

I run a 557 and mileage is not something I have ever considered. While a big gas engine can be cool, and will make some power, those ponies will be thirsty and you will have to feed them.
Not too sure about that overdrive unit, but if the manufacturer claims 420ft/lbs of torque capacities, you are gonna kill it with even a mild 460.
Some mild aftermarket heads can be very worthwhile, and may not require as much work to get the flow numbers requried to achieve your goal. This will depend mostly on your machinist, and the capabilities of the shop. Stock heads can net these numbers, but will require some work to utilize the desire to run roller equipment. You will have to do a cost comparisson for this to see which os most cost effective. IN most cases aftermarket wins hands down. Just be sure you know what you are buying if you buy used. Some mistakes can get passed down and make less power than a conservative set of heads.
Your cam selection is gonna be interesting, and the remaining requirements of the truck will probably be a determining factor. Things like vacuum assist brakes, vacuum accessories and cooling will also come into play.
You can have your cake and eat it too, but this is not gonna be super easy on the pocket.
I am a gas engine fan, and I love to build them but they have their place, and if you put a giant trailer behind one, the diesel usually comes out on top. Trust me I am not an diesel fan, but they do have their place, and I respect them for the power they can create.
Probably cost a ton less money to build a diesel too.
Consider me subscribed to this thread. Interesting thread to follow.

 

On your paticular situation I wouldn't stroke I would install a blower on a nice built 460 .030 which is around 466 cubic inch. On propane you need to install stelite seats because the fuel is really dry and those seats are very tough but a little expensive. A nicely ported 460 headed b@m 6-71 or 8-71 would do the job nice. but need to install nice rods and aftermarket crank to make bullitt proof. A R P bolts on everything. If running gasoline need intercooler under blower. If propane you can get away with out cooler. I would have to check on compression because I never ran ablower on propane and wonder what compression you would need like 9 to 1 maybe higher. You can change pulleys to get higher pressure on blowers. Call the www.blowershop.com for more info on your situation. If you can make about 1.6 hrspwr per cube thats 768 hrspwr with 466 ford. These are modest numbers and can go higher. Basically need to build a thousand hrsp capable engine and be reliable. Now can your drivetrain handle the torque it will be higher than that number. This can be done with ported dove head and built btm end on 460 ford. What fuel system are you thinking. Their is a canadian company building the propane systems but forgot their name with O2 monitoring but their throttle bodies are only 600cfm and you would have to do a twin bodies tied into one computor if this is what you are a thinking about. The other problem is you propane tank is gonna need to be large so when pullin vapors from tank instead of liquid propane. If you do buy heads buy P-51 supercobrajet heads perfect for situation and dyno proven with no porting necessary. Jon Kasse racing product and inventor. Hope this will mess with your head a little. You will need to research the tranny to handle this because the np435 can not handle the torque. I will split the case near pto access near lower shaft If you hook up hard. Ran a centerforce dual friction clutch when we broke tranny. Gonna need a built c-6 heavy case with all the cool parts,aftermarket overdrive that handles around 1200 hrsp forgot their name but a friend runs one and I'll check into the name later. Also check into you tube ford F2000 off road racing truck 1000 hrspwr with 460 twin turbo nice truck.

 

For got to mention we broke tranny 3 times with blower motor when it carried the front wheels on 40" tires.

 

Do what 428f250 said. Build a 545 or 557 which will be an absolute powerhouse but you might need to upgrade the rest of your drive train.

 

I have a 533 4.3 stroke engine but fuel mileage sucks and need to get bigger radiator/capacity. heats up when pulling big mountains. the 472 does a good job all around and a lot cheaper to build for pump gas motor and mountain motor. don't turn over 5500 much for what its used for. If I had a aftermarket crank I would install a blower if wanted to. need get compression down around 9 to 1 or lower also. Ran a 429 for yrs but have to wind up a little to do the job. Less stroke and that where the 4.140 stroke or 4.3 or 4.5 work nice on lower rpm. 533 needs around 950 to 1095 cfm to work good all over.

 

Ok, is there a manual tranny that can handle 700hp? Ok what do you guys suggest, my 73 F-250 4x4 i want it to tow pretty good, i want to do a 205/203 doubler, a manual tranny and an overdrive for better highway rpms. the biggest tire would be a 39" swamper, it will have a Can-bak soft top canopy with a ladder rack thats modified and reinforced to support 1000lbs w/intergrated light bar over cab and a semi exoskeleton connected to the ladder rack. The truck will be pretty heavy but i need it to be capable offroad. I would like to feel the power in the seat of my pants, which powerplant with manual tranny would you guys suggest? i dont mean to be repeditive in my questions i'm just trying to be through. I appreciate any input, thank you.

 

Does your truck have a 360 fe in it currently cause if it does i would build 410 fe series which would be plenty powerful in any light truck.

 

first off do NOT go with a blower motor it's really expensive and major time picky on a 460 based engine, as well as really don't like dirt so using it for an offroad setup really isn't a good idea except for racing situations. The only advantage is a blown motor works better at higher altitudes but even the pass over Mt Hood really isn't high altitude. But since they are so finicky about tune I would only consider a blower with EFI so the computer can make the proper tuning changes as altitude changes otherwise your looking at engine damage as a very real possibility. And then there is the extra $4000 dollar cost of the blower, PLUS the added cost of the required better internals then would otherwise be needed (like an aftermarket block would be a really good idea, billet rods would be on my lists, possible oringing the block etc) so you can figure you are already in teh hole over $4k before you even start on the engine, figure a good $15,000 for a proper setup blower motor, you can build a pretty decent motor for a lot less.
also don't do the 545 557 engine use the 4.3" stroke deal at .030 making a 521 for best longevity.
Also don't use the P51 heads for your stated application they are the SCJ heads with the bigger ports making them better at top end performance then bottom end and mid range power (although they do work well in the mid range) which a competant engine person would have known off hand. The TFS streets are a much better choice for this application even out of the box and can easily reach your goals and have the advantage of being able to use standard manifolds like a stealth instead of only being able to use teh CJ types.
The P51 heads would be better suited for a mild race engine then a work horse. remember it's not hp that moves the truck it's torque and it's also torque that you feel in a street driven vehicle.

 

wyoming4x4 let me make a guess your on your second quarter of school at WTI, or in the hotrod program and have learned all there is about hot motors in there.

 

Well, if Catman 24 dont get anything out of that, I sure did Monsterbaby. Shucks, with a 36' motorhome totin around 23,000 lbs, I would probably be tickled pink with a 502 cube, that is if the C6 & U joints would hold up.

I aint the sharpest person on the block, & most all I know is what I've put my hands on, but if you want those 460 heads to survive all that exhaust heat pulling something, better install Stellite guides, Stellite seats & valves or get youst to pulling the heads off.
Neil

 

Well I've been in the 460 big block world for about 20 plus yrs. I was a student/graduate of School of automotive machinist about16yrs ago with judson. I now hang with some bigger hrsp guys and also use Mpg heads for cool stuff scott know me by wyoming. When livin down in texas and muddracing with doubletrouble racing for about 7yrs learned a few things, houston area. Then I move into higher elevation like 4000' and up to 10,000' elev stuff. I thought I was a decent engine guy back in the day but high elevation tuning is another problem within itself. 400 hrsp motor in houston is a 300hrsp motor up here. Been doing it about the past 10 yrs now. I don't race anymore but help guys tune up their rigs and I just wheel my truck and have fun. I've been learning around the superpullin mods and ford mountain motors and some ford dragster stuff a little lately Greg hunter is the owner and driver. He lives in sheridan wyo. and He's canadian guy. Pretty good fuel man and independant. I do know your smart at what you do but kinda harsh. Been learning these enginemaster stuff here lately and some cool new stuff is coming out for us. Been applying some of these products to my toys and they work nice. You have a nice day? Maybe well have a armwrestling match some day and I can roll you.

 

Also forgot to mention I usually work on 7044 cubic inch motors and bigger for a livin. Twin turbo'd. Some are even blower'd and twin turbo'd Some two stroke and 4 stroke. Some engines have cylinder heads and some don't have cylinder heads with twin cranks. Some are dual fuel natural gas/diesel some propane.I'm always learning and playing and stroked 460 are what I do for fun on the side. maybe I could help educate some of our fellow ford guys with what I know and learned over the past 20 plus yrs but if this is not welcome its somebody's loss. I work with caterpillar and waukesha, fairbanks morse, ajax ,arrow, MEP, pielstik, and several other engines like fords and chevy's. I've pretty much broken just about everything that can be broken in oem form on a older ford truck due to horsepwr and big torque back in the day. I'm smarter now and try to not repeat mistakes that I've learned from the past. Please don't call me out again like this or I'll show up in IOWA. Used to live near you yrs ago. O by the way like the mud truck.