Straight Six Cylinder versus 350 Swap

[Beaker]

I purchased a 1950 Chevy 3100 with a straight six cylinder engine, would it be worth rebuilding or would I be better off swapping it out with a newer 350? I'm kind of curious on the gas mileage the old straight six cylinder engines received and the amount of horse power produced by these power plants. Would it be a little more expensive seeing as these are not the typical rebuild? Can you even get parts for these engines?

[curmudgeon]

Depends what your goal is for the truck. Assuming you have the '50 original 6 cyl, that would make it a 216 splash oiler, not worth rebuilding unless you're after the stock look. The better choice would be the '54 and later 235/261 stovebolt, but more cost to rebuild than a SBC with less power. Of course the SBC swap is well documented and judging by the number of them seen at show, one would think they were really a factory option.

If you are looking at power/mileage, nothing beats the LS3/overdrive auto combo. I personally have a 261 with a Saginaw in my '54 and get high teens, but it's slow and I have a 3.08 rear, ( plus my last build had a SBC). I'm lucky if get 150 hp out of the engine, but it looks period correct with a little more low end torque than the orginal 235.

[mr48chev]

Originally Posted by curmudgeon

Depends what your goal is for the truck.

That is the best answer to any question about "which way should I go with my truck" that has ever been posted on here.

In the long view, what do you plan to do with the truck driving wise? Then what are the plans for the whole truck appearance wise?

If the plans are primarily to have a "restored" look to it and drive it to cruise nights and local shows or just put put around the local area on weekends keeping the stock engine or changing to a 235 for pressure oiling work great. You can still make a couple of events a few hours away without worries except it takes a bit longer in the slow lane and the "not the freeway" roads become more comfortable to drive and more fun.

If the plan includes a number of long trips to far flung events and vacation trips that include several thousand miles a later model engine that has more power and can run the truck down the freeway at real freeway speeds will probably be in order. That could be a good running later model straight six, a bigger V6 like a 4.3 or a V8 of choice.

If you plan to keep the I beam and leaf spring front suspension with the stock steering I'd suggest going with an inline engine because there is always the hassle with the stock steering box on V8 swaps, which in fact is the only big hassle on V8 swaps except for swapping rear axles to open drive.

If you are planning on swapping the front end out to an independent setup then the V8 swap isn't a problem except deciding which V8 to use.

First you need to kick back and decide exactly what the total plan for the truck is though, how you want it to look and how you plan to drive it. We have folks with many different concepts on trucks on here. That runs from the hard core restorers who don't want any changes from the way the trucks rolled out of the showroom, the horsepower boys and girls who build trucks with "more power", the traditional guys who build them the way hot rodders did 50 years ago and the progressive rodders who Have shelves full of billet parts and wheels that they have pulled off their trucks when something newer came along and they had to upgrade to keep up. We all enjoy our trucks in our own way. Some of us put thousands of miles a year on them, some only drive them locally on weekends or cruise night and some load them in trailers and tow them behind their big late model trucks because they don't want the trucks to show wear because it might cost them an award at a show.

Just as on engine choice we don't always agree on other things that guys do or don't do on their trucks. The billet boys don't understand wide white walls and flipper hubcaps while the wide white wall brigade often questions why someone would put 22inch wheels with three inch sidewalls on a 60+ year old truck all the while the restorers are shaking their collective heads at the bunch of us.

The one thing we are amendment about is building a safe truck to drive on the road. If the folks in the group see something that they don't feel is safe they are quick to point it out and explain why they feel it is unsafe and offer viable solutions to correct it.

[NEWFISHER]

I have $4500 in a 250 inliner that produces just over 200 hp and gets 20 mpg at 60 with 3:73 a 700r4 and 29" tall tires.

You could install 4 to 6 reman or used 350/350 combos for that money and have as much or better power

A newer LS 5.3 motor and 4l60e trans can be done for a little less and have great HP and fuel economy not to mention longevity.

So why did I spend a ton on an inliner that gets 20, pulls my 4200lb Vintage trailer and lets me drive it to work in the fast lane and pass the commuter cars....because I could is the only GOOD answer I can think of. Follow 99% of the rest of those who have done the V8 swap and be happy or throw a ton at an inliner and draw a crowd, raise an eye brow or confidently say you have a " buzzen half dozen" under the hood when you are at the cruise, gas station or show.

I had the same question before I started and it all comes down to > what do you want out of it > how much can you spend > what are your fabrication skills> 6 or 8?

[Speedbumpauto]

Comparing that 250 to that early 216 or 235 is not really apples to apples. The huge downside to those earlier engines is they didn't have full pressurized oiling systems. They worked OK for the time but are a serious impediment to making any horsepower at any rpm. I respect doing an old engine for the "not the same" look but unless you're part gearhead, you'd be way better off with the plain vanilla choice.= small block V-8.

[NEWFISHER]

" unless you're part gearhead, you'd be way better off with the plain vanilla choice.= small block V-8. "

Exactly

[PDW HOTRODS]

A few weeks ago I was at a show and saw a 55 Chevy car with what I thought was the most interesting and maybe coolest engine of the show. It was a 1969 inline 292 with a custome made intake and multi port injection. I have never seen this done and almost everything else Chevy at the show was stock engine or V8, so it realy stood out. I loved it, but I will go V8 for the cost and practicality.

[torchlight]

I've always thought a Vortec 4200 would be a great compromise between newer motor and keeping a straight 6. However, you'd need to be quite a gearhead to pull it off, I think. I thought about it, but ended up going v8 on my project.
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[lowrodderchev]

straight 6's just look cooler especially when your running a few extra carbs and some polish aluminum goodies or just plane stock and painted

[coralhead]

I keep running the idea of putting the straight 5 turbo diesel/tranny out of my '82 Mercedes 300D when the body gives out again. Tons of torque and great fuel mileage.

[joev]

coralhead... great idea.


joev

[Beaker]

Hi Guys,
Thanks for the great information! The plan is for me to have it as a daily driver and any trips to car shows. I agree the straight six cylinder engines are sweet looking and definitely something you don't see everyday. I'm getting ready to order chassis engineering front IFS and their complete component kit.

Thanks Everyone for the awesome insight and information I'll be posting picks later on. I have to raise a little capital by selling my Suzuki gixxer 750, no love loss. I've owed this truck for 11 years and its time for the truck to receive the respect that is due. Its been stored in a barn with a long time friend a 1977 Ford F150 Custom which is only brought out in the winter time for plowing the drive way. Thanks Everyone

[focusedontheprize]

Similar cross road I came to when I first started. My buddy has a 327 and I could have dropped a 350 in it that he had in the garage. During all the mist of this, I came across a guy who was running a 292 in his Chevy Business coupe. From there I was hooked.

My setup is strictly this - I wanted something that I can cruise in, haul a few things if needed, and have a great gas mileage so the 292/5 speed setup in mine was just right.

We had a huge show back in July in my hometown. The truck wasn't done, but I brought it out and popped the hood. I cannot tell you how many people were around that thing and commenting on how cool that 292 is. I loved it.