250 or 292?

[monolith]

My 250 in my 66 3/4 ton GMC is getting tired and leaky and I want to keep an inline in the truck. Looking for opinions here on which engine to go after.

Relatively cheap 250's come up on craigslist pretty frequently, and so does the occasional 292- I was thinking that it may be cheaper to get one and swap it than to do a rebuild(especially since I'm not too adept with engines yet)on my current engine and don't know a decent machine shop.

I'm NOT interested in a v8 swap- I'm not looking to make a race truck, just trying to keep the truck a simple, mellow, fun cruiser and summer driver.

At some point soon I'll want to dress up the engine with some offy/clifford induction and headers, and convert to HEI. for a bit more "cool," reliability, and pep.

The same intake/exhaust will fit both the 250 and the 292, correct?(non-integral head)

Are the distributors different?

Thanks in advance for your help and opinions,

Baz

[jbarnes67]

Everything will swap from a 194 to a 292. Only problems when swapping to a 292 is that it is physically taller than all others. You will have problems with brackets lining up for power steering and alternator, if not able to get 292 brackets. They are getting harder to find. You can always adapt your 194-250 brackets to work. This is what I did. Exhaust might also get into bind going to 292 due to difference in height as well. I had to add a small 3-4 inch addition to mine to make it line back up and fit. Biggest difference is placement of passenger side motor mount and the fuel pump on 292. You will have to move your moter mount perch to the other set of holes in the passenger side frame rail. Fuel pump is also offset slightly too. Because of this If you already have an aftermarket cam with mechanical fuel pump eccentric for the 250 it wont work with the 292. electric fuel pump will fix this. Lots of racers used to put 292 cranks into 250 blocks. they will fit with shorter rods. But that starts down all whole other road.

Best of Luck

Barnes

[padresag]

you will require the passenger side engine perch for a 292 as it is different than all of the others
ron

[sailed2japan]

I want to hear more about this 292 crank in a 250 shananigan. Sounds like fun.

[ol Curt]

If you want to keep it simple, go with the 250. I had one with a bunch of chrome, dual carbs, headers, etc one and it had some cool factor. It is much easier to produce horsepower for a pickup with the 292. Just depends on whether you want the cool look and the sound or the really fast option with a six.
I bought a book...I think by Leo Santucci some years ago that goes into great detail about building the sixes for racing.

[monolith]

Thanks for the responses! And for your experience, and the extra reminders about the 292 differences, and parts I'll need- I'm keeping the truck non PS/non air for simplicity.

I'll be picking up the Santucci book soon- I'm waiting for the second edition to be released(Barns&Noble says mid January.)

This is such a great site, with such a wealth of knowledge.

Keep on Truckin'

Baz

[murdoc]

I recently did a 292 to a 250 swap in my 65 c-10. I have been VERY happy with the 250. It accelerates a lot faster than the 292 and doesnt consume as much fuel as the 292 either. Not near as much torque, but i just use it for cruising and small hauls to the dump. for around town driving and light service, the 250 is more than adequate. long live I6's!!

[bubba327]

I also recommend Leo Santucci's book. His race motors are getting unbelievable horsepower and torque.
I really like my 230 I have in my 64 . I have a 250 waiting if I need it.

I have been cleaning out my garage and putting some of my unused 6 cylinder parts on E-bay.
It is crazy how interest is from guys in Brazil wanting vintage speed parts for a Inline 6...
Check out the Opala. A Brazilian Chevrolet available in coupe,sedan or wagon and also in SS trim .
Most all had the inline six.
http://en.wikipedia.org/wiki/Chevrolet_Opala

Dare to be rare with a buzzin' half dozen

[Heater63]

monolith,
Pick up a running engine if you can and do a one day swap. Machine work is not cheap anymore.
every single post here is correct and good advice. If your not pulling loads, and just street driving, I recommend you stay with the 250; it will be a little cheaper and easier to maintain and modify. It will rev a little easier as it has a much shorter stoke that the 292. However, if you need to PULL, the long stroke 292 makes great torque. They can be quite expensive to hotrod. You can get Santucci's book, but unless you want to race, you don't need it, just these things for a 250: put in flat top (chevy 305?) pistons, a mild cam, HEI, Offy intake with 4bbl (I like Edelbrock), and headers/exhaust. The next step is to use larger valves and a set of $100 intake lumps you can install yourself. The choke point on these engines is the non-crossflow head.

sailedtojapan, I recommend you get Santucci's book if you dont have one! it shows building heads from aluminum SBC heads, full race advice, etc, etc

[sailed2japan]

We'll see. I've got little Cummins sitting here ready to go into whatever I build, but I've always liked inline 6's. I was watching that video of the guy with the turbo'ed 292 in an El Camino earlier and I got all pumped up. I was curious as to what parts can be swapped into the little guys form a SBC. I read something about 307 pistons going in somewhere.

[Heater63]

All the 250 and 292 pistons had a D shaped relief in the piston.
The 307 pistons are flat top and can be used in the 250 to up the compression a little, but can't be used in 292. In the 292, there are 2 choices, you can get a "liquid propane" piston that ups the compression to about 9:1, these are affordable and available from Sealed Power (Federal Mog), OR, you have to get high dollar forged pistons ($100 each or more).

[greg64]

Both engines have their pluses and minuses; I've run both.

The 292 clearly wins in starting grunt. If you have a heavy load to get moving, it's great. As the revs climb, they start to equal out. Above about 2500 RPM, I think they're nearly equal. My truck didn't get appreciably faster in top gear with the 292 vs the 250.

Where the 250 wins is gas mileage. The 292 is definitely thirstier at the same cruise speed.

No matter which you choose today, the beauty is that most of the parts will swap from one engine to another. This includes:
- valve cover
- distributor
- timing gear cover
- intake manifold
- exhaust manifold

The big things that don't switch are the pushrod covers (different height) and the cam.

I don't have an overdrive behind my 292 (SM465) but that's really what's needed. That engine wants to sit at 1500 rpm and lug away.

The 292 is also heavier and taller, but neither of those are really concerns in our trucks.

I really wish GM had built a big-block sized inline 6. With 454 sized pistons, we'd have a 340 ci 6!

Perhaps a turbo'd 250 would be the ultimate.

[monolith]

Well, I ended up going with a 250.

[IMG][/IMG]

Saw this for cheap on Craigslist (it was listed as a 250 V6, but I called on it anyway and asked.) The guy said it was rebuilt a couple of years ago, then pulled out of the car in favor of swapping a v8. It's been sitting in his garage for a couple of years- he had oiled rags stuffed in all of the openings.

I'll be putting it on the engine stand this week, changing the oil, squirting Marvel Mystery Oil in the cylinders, and seeing if it turns.

Offy triple 1 bbl intake.
The 2 end carbs are functional, but have been blocked off- the motor was run with only the center carb.

The exhaust manifold has another outlet welded on for Dual exhaust- any opinions on this mod?

[greg64]

Good looking engine! I like that intake manifold. If you want to spend some money, have a look at Stovebolt's cast iron split exhaust manifolds. This is what I'm running and they breathe much better than stock.

[gtbrain]

one more vote for the cast iron headers from Stovebolt.

[Crash'd Artwerks]

Originally Posted by sailed2japan

I want to hear more about this 292 crank in a 250 shananigan. Sounds like fun.

I know this is an old thread, but I was doing some searching and ran across this.

The 292 crank has to have 1" machined off the throws to keep the counterweight from knocking the bottom off of the piston. You also have to use 400 SBC rods and 350 SBC pistons. It comes out to 311".

My dad's cousin used to built all kinds of crazy inline 6 cylinders back in his dirt track days in the 60's-70's.

-Aaron
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[DLOE65]

Go 292! You'll be happier in the long run, you can pick up a block on eBay or CL for about the same price as a 250. all the parts are about the same price too.
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[Surfdaddy]

That's one nice looking 250!!! Should clean up very nice. I wished I did that on my 67 camero. 250 with a three on the tree. I've had the 292 in a 64 carryall very good for low end.