I'm looking for a 97 F250 with a crew cab and a 6.5' bed and a 7.5L gas engine. This will be a "project truck" which will, hopefully, be converted to a "dually". I already have a upgraded (0.60" bored out, flat top pistons, Lunati cam with gear drive, roller tipped rockers, and other stuff) engine for it and will be looking for help to convert it to a dually. After an A4OD tranny, a 0.410 rear end will, probably, be used The gasoline engine will be converted to propane and a pair of 12" diameter tanks will replace the existing gas tanks (in front of and behind the rear axle. Also, I will be putting a 20" diameter tank in the bed of the truck for a total fuel capacity of about 85 gallons. The long tube exhaust headers will go to an "X" pipe system and use 3" diameter tubing throughout. Under consideration, also, is a set of exhaust stacks rather than coming out the back. All relative comments would be appreciated.

 

Moved to proper forum

 

I'd skip the stacks since its a 460 big blog and not a diesel. If it were a diesel, I'd say maybe if you can stand the sound. A straight piped gasoline engine...sounds to rappy and lacks back pressure. Maybe put in small mufflers if you can make the room for them.

Dana 80 axle for the dually, just remember that'll be an extra $110-$200 per tire so instead of say $600 it'll be about $1000 for a set of 6. Otherwise either keep the Dana 60 or go with the SRW Dana 80.

Do a Dana 60 swap to get rid of the TTB if you want. I'm not a huge fan of it but it is a nice IFS.

You do realize that using propane as a fuel, you'll lose some power (20% or so) and your fuel economy might go up by 1-2mpg. It has it benefits, but unless you are off road a lot in steep grades or your going from a high elevation to a low elevation, you probably won't see a huge benefit to propane injection. Propane does self-adjust to elevation changes which it is why its great in the rock crawling world.

 

Thanks for the info about a Dana 80 rear axle for the dually conversion.
The exhaust stacks are just an idea at this point. I had an older F250 and put stacks on it, but while it was "sorta kool" I'm not sure that there'd be room for them in the front corners of the bed when I stuff a 20" diameter propane tank in there.
I ran a 1978 Lincoln on propane when I as in CA and drove up the west coast to Canada & back on straight propane with NO problems.
The motivation for propane is that it costs about 60% of gasoline and only has about 10% less power than gasoline. Another thing about propane is that it has an octane rating of about 110, which means I can run a higher compression ratio with no knocking. I have in mind to, perhaps, add a supercharger some day, but money is a BIG factor. 8-10 lbs boost would help overcome the 10% less power of propane
I'm having a LOT of problem finding an F350 crewcab gasser with a short bed (with the long bed, it's just too long) Has anyone heard of getting a diesel and replacing the diesel engine with a gasser? (that's probable heresy to a lot of people) There are a fair number of F350 diesels with short beds and doing an R&R of the engines might be the way to go. That way, I'd have the HD axles I want.
Has anyone heard of getting a F350 long bed and shortening it to accomodate a short bed. I'll bet that this would be VERY expensive, too, but if I started off with an F350 long bed dually and cut it down, I'd have my dream truck with all the correct axles and the crew cab with a short bed.
I guess I'm just testing the waters for what's out there and trying to not go too crazy with ideas. At this point, I'm thinking that I'll probably end up changing out a F350 diesel with my 460 gasser. Anybody have any comments other than telling me I'm totally insane?