73 K10 - what to do - blank slate

[69Tom]

I'm picking up a 1973 K10 short bed this weekend. It has no engine or transmission, and I need to start planning somewhat on the drivetrain. Historically, I'm a numbers matching guy. However as this has nothing, I feel like I can do what I want. Basically, I want a truck I can take on or off-road and not worry about it much. Some thoughts:

• I've always liked the older engines because I feel like they're way easier to work on. However, I do like (the maybe false) reliability of a modern engine. I don't, however, like the reliance on "a computer" for it to run. Hey you never know what could happen (clipping, shutdown, cough cough).
  
• With gas seemingly not getting any cheaper, that is a factor here. I mean, if I can get 18 or better a gallon, I'm ok with that. It's just got to be better than my 10 mpg in my 74 454 I have at the moment.
• As K10s came with small blocks, I'm cool with the 350 for an older engine. I'd probably want to get the HP up in the low 300s and torque in the high 300s/low 400s.
  
• Carburetor vs. fuel injection? From what I've been reading, it doesn't seem like the Sniper-type systems are that awesome. Plus the computer..... Not sure here.
  
• Transmission: TH400 vs something with overdrive for highway. Not super sure here. I'm sure you guys have some good thougts on this.
  
• For the first time ever, I have a transfer case to think about. I'm all ears on this one. Whatever gets the most suggestions wins. I'm sure the transmission/engine combo may greatly factor into this.
  
• Overall, I generally like a stock look, but going with 15 x 8 steelies (6-lug - I somehow found a set for under $600) on this with a 30-32" tire. I don't want Big Foot here. Just a beefier stance than the stock 6" wheels.
  
• Do I build the engine myself (if going with an old block)? Do I go with a pre-built engine (I have concerns with quality here; any reputable builders with value)?
  
• Sadly, cost is always a factor. I don't have an open checkbook here. But I also realize what I need to spend/have to spend if I choose certain options.

Well, that's about it. I'm open to everyone's opinion here, as I know a lot of you have already done this and have a lot of experience when making different choices from stock.

Thanks for the help.

[JJH Jimmy]

I think trying to get 18 mpg in a squarebody going to be tough but there are my suggestions.

Buy a crate 350 with roller cam for reliability.

Find a good used quadrajet carb and have it rebuilt by a reputable builder.

700R4 trans since computers aren’t your thing and have it rebuilt with all the upgrades to make it last. You should be able to pick up a good core for a couple hundred dollars. (I personally hate 700r4’s but they can be built to last). You will never have good mpg with a 3 speed auto.

Or

If you don’t mind a manual nv4500.

Np208 transfer case because they are plentiful/cheap and are fairly reliable.

I think it will be hard to have an engine rebuilt cheaper than buying a crate engine unless you do the work yourself. Buy a crate engine from a reputable company that offers a warranty. I have a blueprint in my K20 and have been really pleased with it.

Put 3.73 gears in it.

With all that being said you might get 14 or 15 mpg.

That’s just my thoughts! Sounds like a fun project.

[JJH Jimmy]

You might want to look for a 80’s 4x4 squarebody donor that has a bad engine. Then you would have most of what you need and then purchase the crate engine.

[Dead Parrot]

Check your tire size/gear ratio/transmission vs RPM with one of the on line RPM calculators. You don't want a combo where the OD RPM is too low. You don't want to find out after the fact that your gears are wrong for your $1000+ set of tires/rims and something has to change. Changing either at that point gets expensive.

More HP/torque often equals less MPG. A 'go fast' truck often goes through gas fast.

Use the results from the RPM calculator to pick your cam/intake. A cam that works best at 3500+ probably won't give good results in a setup that spins at 2300 in overdrive.

For a do it yourself motor, 350 + vortec heads + roller cam.

If you go computer/injection, get one that include the ability to control an electronic trans. Several computerized overdrive trans options. But stand alone trans controllers can get expensive. If you go computer, might as well look for some variation of LS transplant.

[cj847]

I would encourage you to embrace the digital age and go with an LS swap. The best way IMHO is to completely ignore the aftermarket. Get an LS and trans with < 250,000 miles and do not touch it (well ok you can replace a gasket only if it is visibly leaking). It was running when the truck was wrecked - it doesn't need to be gone thru, cleaned up, tinkered with, etc.

Just a reminder, the LS engine has been around since the 1990's. The average mechanic does not know how to work on a small block chevy. Much less adjust a carb.

Get a run of the mil 5.3 with 4L60E from a 4x4 vehicle. The issue with transfer case can be solved by using a passenger drop 241C from an 87-90 chevy truck or suburban.

Regarding cost - you could make this cost more than $10k by buying aftermarket stuff from JB conversions; Holley, etc, etc.
Don't waste that money. There is nothing wrong with the stock parts. Use 100% GM factory stuff and it all bolts together and works.