Technical What’s your opinion?

Hello it’s been a while since I’ve been on here. I’m getting ready to build a 54 GMC with 10k original miles. A true barn find. I want to get rid of the 6 cylinder and drop a SBC however we want something really cool and period correct for that time to top it. Maybe a Tri power, stack etc. What’s a reliable set up that can maintain the cool factor?

 

Where's the pics?

 

Just a note, when you put the V8 in, offset it to the passenger side (maybe an inch).
It will help with steering box clearance.

 

You can do whatever you want with it, it's your truck, but those GMC inline 6's can make incredible power and were pretty legendary in their day (they are not the same thing as the Chevy stovebolt). There's also a fair amount of speed stuff made for them although some of it is pricey. You might consider using that engine with a different transmission and rearend.

There's nothing you can put on top of an SBC that makes it cooler than a big GMC 6. At least, not in my opinion.

 

It might be a little lame, but a 10k mile survivor, a "true barn find" I'd leave the 6 in it. How about a peek under the hood?

 

My opinion ... take what you want from it. A 292 Chevy inline six with dual carbs and split exhaust. It'll run good and sound good with the right exhaust and make good power too.

 

It's yours to do with as you want but you are asking for opinions so....
SBC's are as common as water. That inline 6, all dressed up, with a few speed parts added will knock your socks off with power and torque. Be different, people will dig it.

 

First questions that need to be asked before you lift a spanner/wrench are:
"What do you want from the finished truck? What will you want it to be able to do performance wise?"

Any V8 swap into a '54 GMC pickup will be a move away from the inline six that was standard. Small block Chev is the obvious choice, but you would probably like what a 350 will give you. The power/torque will get a heavy truck moving quickly. The beauty of the small blocks is that all of the sizes look virtually identical, and what you do with the exhaust manifolds and the air cleaner will have the most visual effect. Easy to keep it looking old school, if that is what you are after.

If you are fanatical about the old school thing, then the 248.5 cubic inch six will be good with a little extra muscle stirred into it. Wise transmission and rear choice/gearing will help a lot. Six can be a real cool number...........

 

283/327 for era theme. 348 'W' motor may be a bit wider than the sbc. Lot's of sbc's are offered up on the 'net due to the Ls lemmings trend.

 

I’m looking for a vintage period correct mod. Just not sure what’s the best roughy as far as carbs and manifold. Carter/ Rochester etc. is better? Tri-power vs stack etc.

 

Yep, that is correct if you want to stay within the HAMB pre-1965 guideline.
You could fudge though, and stroke a 327........ (Ssshhh, that would be a 350, and not many people carry a welding rod and a steel rule around with them. If you have to ask, don't bother.)

 

I’m fine with that but any recommendations on the manifold and carb set up?

 

Tri power set up's need good cores or at least good builders to start with. There are a couple of vendor/carb kings here that may assist your quest. Building a motor around this induction (custom ground cam) ignition dialed into the equation will net the greatest success in throttle response, drivability & fuel mileage. Car 4 speed's are listed on the Craigslist/FB market places.

 

Be more concerned with good brakes and steering.

 

https://www.facebook.com/marketplac...wse_serp:d31e2ad6-7a68-4883-9560-c4d0960aca3c This is a example of what is out there this moment. Research the board for threads that address the sbc/tri power question.

 

I'm probably not the best to offer advice on that. If it was up to me, I would run a single four barrel and custom make an original-appearing oil bath style air cleaner that housed a more user friendly round paper element. If done well, the lower part of the housing would hang down around the carb and disguise it a bit.
https://www.jalopyjournal.com/forum/threads/oil-bath-air-cleaner-to-paper-filter-conversion.638965/

Tri power setup would look cool too, but a fair bit more involved to get it right. Get real good advice if you go this way.

 

J2 Olds or a Nailhead would be a real jaw dropper if you choose to ditch the 6. Dual quads with the small Vette style air cleaners on a small block looks real nice too...

 

While I would keep the 6, whatever engine you choose to put in, change as little as possible and keep the 6 to put back in. Those GMC sixes are tough.

 

I agree. you will not be happy with the handling and ride of an original front suspension. Especially if you decide on an early V-8
Nice truck!

 

How about this, Factory Tri-Power?!

 

Wow it looks great! Congrats.

Its a slippery slope. Drop in a V8 and I'd upgrade the brakes and on and on.You'll need a transmission, diff, drive shaft etc etc. If you arent doing all the work yourself and want new/rebuilt components you could easily spend nearly $10k in parts and labor.

Wanting something 'cool and period correct' personally I'd get it going, some simple performance upgrades like split intake, carb etc on the 6 and focus on cleaning it up and perhaps lower it a little. Drive it for a while then make decsions about drive train etc. You may find you fall in love with it as is.

 

I ran a 250 cu in 6 cyl for awhile with a 700R4 and a 3:25 rear end ratio and though it ran fine and cruised the freeway good, it still lacked power in my opinion. I now have a crate V8 engine and I love the smoothness of this set up, it's like driving a more normal car. But if you don't want to put a lot of miles on the truck then I would work with the engine you have and save a lot of money and time. Spend the money on the things the truck needs to be reliable and safe, it will be a ton of fun doing that.

 

Agree with this. If this is a 261 Jimmy 6, you really need to have second thoughts about the sbc transplant. A good Ohaul, and it'll pull down a house and last your lifetime.

 

A 3x2 set up with 2-jets would be nice and work very well even on a tame SBC. I sold this one years back.

 

I'm a Ford guy, but LOVE big GM 6 cylinders. Dual or tripple carbs, cam, split exhaust ... sound & run GR8. Squablow's idea is the way I'd go. That is a really neat truck !!!

 

My opinion, the truck's value are best as it sits right now. Survivor trucks of the era are ultra-rare in that shape. Well, it will drive like a TRUCK for sure and often the rear gears are steep.

It all depends on what you want to do with it, which is okay by me. If you want improved safety, comfort, power and reliability, your work is cut out for you.

 

Re read what you wrote. You already have it. Ditto what @Squablow said.

 

A friend of mine although Chev nothing says you can't do to GMC. Just a thought.