Big inch high torque SBC. TPI or blower?

I'm looking at building an older chevy truck to tow about 10,000 lbs with as much eas as possible. High rpm's aren't that important but I'd like peak HP to be above 5000 rpm's. A big block would be nice, but I don't want to spend much over $5,000 and BB heads just aren't that cheap. Lets just say for a baseline that I want 500tq by 3500rpm's and 450hp above 5000rpm's. I'm looking at either a 142 mini-blower or a TPI unit of some sort. How can I get a stock TPI to work with a big cube small block? Affordable Fuel Injection sells a TPI by First for less than two grand, anyone have any experience with this unit? From what I've looked at, the Stock TPI's make great low end torque but don't have a top end above 4600rpm's without shorter runners while the super ram and mini ram will rev plenty high but often give up 30 plus lbs in the low end, please correct me if I'm wrong. I think a good starting point is a 412 from PAW, the unassembled short block is only $1595. If anyone has experience with TPI it would be awesome if you could pass your knowledge on to me. Anyone think they can make me a build sheet to work from or give me a link to a build similar to what I want?
Thanks to you all in advance.                 Corporal Scott Sumner, USMC  

The money you are going to spend on that small block could be spent on a big block and you should be able to build a decent big block for $5,000.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

I really don't want the extra weight of a big block, but if someone knew a good head and cam combo for a newer 8.1 liter vortec I might consider putting the 300 pound heavier motor in a truck. I think the stock motors put out 450tq and 340hp at about 4200rpm and with boat headers that goes up to 490 and 390 at about 4600rpm. With that big of a motor I would like to keep the fuel injection to keep a little fuel mileage. If I could get a 8.1 liter MerCruiser boat motor for cheap, what would I have to do to make it work in a truck? Can anyone help me out with a TPI small block or 8.1 liter combo?  

Would the heads and fuel injection from a vortec 8.1 fit on a 7.4 mark VI. Would this make more power than the stock 7.4? I was just wondering because there are more and cheaper aftermarket parts out there for the mark VI than the 8.1 vortec.  

What about a twin turbo setup using a couple of cummins 5.9l turbos and a caddy 500? Would a turbo from a 5.9 be able to spool up fast enough for 250 inches of motor and not slow the engine down at 5000 rpms? This would weigh about the same as a N/A BBC with iron heads, maybe just a little more with a intercooler. Any ideas?  

When I said big block I was thinking of a 454 or 396 big block 500tq is not a hard task with either engine.
Turbos and all this other stuff I think will kill the $5000 budget for sure and is not really needed.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

i was planning on build a few years back that never happened because I sold the truck but here it goes. 383 stroker with vortec heads and a decently big hydraulic roller cam on a TBI engine,  yes I said TBI,  aftermarket throttle body(not the gay one from holley) with big block injectors, some single plain intake with TBI adapter,  this was just a thought and I put it together on the desk top dyno which might be in the ball park  +-like 40 or 50,  but it said around 450 torque at like 2000 rpm and like 350 horse at i think 4500,  not quite what you are looking for but close  

in think 500 is a little high for a sort budget small block. i would go with a big block like pontiac man said. you can usually find cheap 454's. get some rectangle port heads and intake. should b some where close to target  

tpi units hugh, here we go, for starters a factory tpi unit is good for around 400hp, after that you'll have to go aftermarket.
tpis makes a really good intake, large tube runners, big mouth base, and ported plenum, you might be able to score one online if you have the time.
i'm guesing at 35#hr injectors should work quite well, they did on my 408sbc.

there is an articale called "ten times the torgue" on the comp cams website that will give you a very good idea of the torque curve each manifold makes.

first injection is cheaper yes, but the sheer size of diameter of the runners might mess up your resonance tunning. as of yet no one has back to back tested this on an engine, with good readable results, and enough spec data to make good use of there test.

a tbi computer, will easily run a tpi system, it will just be batch fire, witch opens up the posibilities, of both car and truck v8 injection computers, i would recomend a custom chip be made, for said motor

your $5k budget will put a train on it, you can both supercharge tbi and tpi systems. torque king will be tpi.

here's what i would do if you already have the 412sbc $1595
get a tpis big mouth intake,large tube runners, and ported plenum, with factory fuel rail, and pressure regulator, $800-$1000. off of ebay
external hi pressure fuel pump $180
224/234 hydrolic flat tappet cam from summit $120 including lifters
vortec 059 casting heads, $800
no need for the high lift set, the summit cam has .442/.452 lift i think
timing chain $80
35lbhr injectors $420
custom burned chip $400
cpu from truck, or car ( junkyard ) $100 ?
probably the smartest thing would be find an old tpi Lb9 motor, harness and sensors $500? out of an 85-92 camaro/firebird then you can use the accesories pullies and brackets, ect.
hooker super comp 1-3/4"long tube headers $500
how much is that so far... top side $5595
john leignfelter's tpi motors only used 218@ cam at .050 intake duration after extensive testing he found that, that was about perfect for the tuned runner system. it's your choice how much low end grunt do you want to give up.


you'll still need to finish your exuast system,$450  cheapo jobber
beef your transmission $1400

or you could get a camaro/firebird factory tpi 350 L98 from 88-92 years
from a junk yard then rebuild it. $2000
vortec, or ati procharger with aftercooler $4000 aprox
15psi boost= 500-550hp, 450+ftlbs
and still net around 20mpg, granted your gearing is right.
thats $6000

i pusonaly built a 408sbc wth 18cc dish pistons 5.7 rods
and 86 trans am tpi 5.0 heads ( home ported )
224/234 summit cheapo cam hydrolic flat tappet.
factory exuast manifolds, full exuast.
g.m. factory tpi intake, with 35#hr injectors, and speedpro cpu.
my rear gears were 3.27:1 i believe 70mph = 1800rpm 26? tall tires = 245/50/16
with a factory 700r4 transmission i could send that puppy sideways at 45mph.
but my first transmission lasted a total of 3 days.  
my second trans didn't fare much better.
then i switched to a manual trans- t5 out of an 87 trans am, with a  new factory clutch
the first time i went for rubber in third gear i smoked the clucth, so bad it wouldn't lock up under full throttle anymore.  
play with fire, your bound to get burned...
the factory clucth is rated at 350ftlbs, so's the trans, so i was glad the clucth went and not the trans.
that cars made an expensive yard ornament for the last several years...
i was getting 18mpg and pulling 19inches of vacume  

the next question is does fuel economy matter?
if not a big block with factory heads will easily make your power goals, get the book, "max performance big blocks on a budget" and it will take the most abuse, as well as more than likly be the cheapest. ( well carburated any way)

the small block and tpi will net you the best economy,
the blower one, and big block might come out pretty close to the same.
with the blower being more efficent, given a proper compression ratio is used.
i wouldn't go under 9:1 but that limits root boost to about 7psi.

i could give you exact prices and part numbers, but that would take a few hrs of searching.