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will a 235 have enough hp for highway driving?

depends on what you're hauling, how big a hurry you're in, and particularly what your rear end gearing is, not hp

Bill

Absolutely. However Squeeze is correct about how it is set up. There were millions of 235 equipped cars driven in the 50'-70's out on the superslab.

A few years ago I was part of a group of vehicles traveling together by highway and freeway for 1,600 miles. One of the vehicles was a '57 Chevy with a 235. Since it was the only one not towing something, and because the driver was a little wild, it was the fastest in the group.

Add a trailer and I'd want something other than a 235.

what type of set up (trans rearend) would yall suggest to run highway speeds

If you are referring to your 1954 3100 with an original enclosed driveshaft rear-end (3.90:1 ratio), you could easily run 60-65 mph with a conversion to a 3.55:1 ring/pinion combination. Larger diameter high-profile radial tires help as well.

Of course, the truck should have a tight, aligned front-end and a well-maintained braking system.

John,

Call up Patrick and get his catalogue sent to you it will explain a lot of options and answer a lot about the rear gear set up, trans & using the 235. Here is the link:

http://www.patricksantiquecars.com/chevyparts.htm

Hank

said this before, but I have my original 235, in a 1 ton panel truck, and towed a trailer with a 1950 Buick over 200 miles. no probs. but then, I know not everybody is ok with certain things. experience helps too, you just have to learn that although both are perfectly ok on the interstate, there IS a difference between my wife's Toyota and my 1959 truck. MINE NEVER GOT A RECALL!!

cool!any more sugestion on trans rearend set up? thank john

The 3.90/3.55 swap, although an improvement, may fall short of what you find comfortable - it only increases MPH by 10% at the same engine speed.
If the low-vibration, low throttle opening cruising speed was 59 before, it's 65 now. Is that enough of an improvement for you?
Biggest improvement: overdrive transmission with your existing ratio.

ask patricks about the 4 speed saginaw tranny swap. that requires a little more work. shortening torque tube by 2.5 inches and a yoke conversion. but with the right saginaw(there were several) i have heard an easy 75 mph w/ the 3.55 rear conversion.

What is the high gear (fourth gear) drive ratio on a Saginaw? I thought that were 1.0 (same as an stock SM420)?

I thought that Patrick's extols the virtue of better ratios of the Saginaw's gears (for better 1st gear and better mph ranges between gears), not the final drive ratio (which affects the 4th-gear rpm@mph).

http://www.yearone.com/updatedsinglepages/Id_info/muncie.asp

The Saginaw and all other factory 3-speeds and 4-speeds were 1:1 final drive.

The SM420 is a better trans than the Saginaw, unless your trying to anchor your boat.

A friend has a mildly modified 216 in his half ton and now with a T-5 trans it loves the freeway. The 235 will be the way to go but you'll still need help with some taller gears.

My dad had a 1954 Chevrolet 4 door sedan with a 235 and Powerglide and pulled a 16 foot Shasta trailer through the mountains of upstate New York with it. Not to mention 3 kids and my mother on board.

was the poerglide auto or manual?

if i swap out the rearend and the trany for a later model what set up and doners would work best?

An open drive '55-'62 3rd member can be swapped into your existing differential housing, There will be some modifications needed to the spring mounts (welding the pivots) to allow it to work. common ratio is still 3.90, but it will allow you to use an open drive transmission, such as the T-5 or Factory style 3 speed with the Borg-Warner overdrive.

I have a B-W overdrive, 3.90 gears, ans 30 inch tires on my '55, it will run 70+ without any problems.

why was your mother on a board?

I had a 235 in my '52 3/4 ton. Biggest problem with this engine is its lack of power. I did everything I could with it and I could do 65 on the highway stretching it to the limit. I had to upgrade my carburetor and went to a Pertronix electronic ignition. It ran as good as it could. It's just such a weak and low rpm motor. Even with taller gearing in your truck, it will slow down so bad going up hills that you'll end up having to drive on the shoulder.

Best thing in my opinion for a 235 is to upgrade it with modern technology as much as possible.

65 on the highway stretching it to the limit

But... was this lack of power, or turning too fast?
The 235 has somewhat more power than some more modern L6 engines such as the 170 slant, Chevy 194, Ford 170, etc., and 65 mph doesn't require anywhere near 100 hp unless you're driving a box truck uphill.

I disagree with the lack of power. As I said, I've run mine 70+ without any problem. The one time I did have an issue with accelleration, it was a clutch adjustment issue.

I have no problem cruising at 60-65 and passing at higher speeds (235-261 engines and 3.9-3.55 rear ends).

All with drive-trains, brake systems, and front-ends/steering in good shape (and with LT radial tires).

I have a 55 1st series 3100 with a bone stock 235. Dyno'd with 89 RWHP.

It has a 3sp with OD, 3.90 rear axle and 215R75-15 tires. It cruises nicely at 60 MPH / 2000 RPM.

It has enough power to accelerate to 75 reasonably well if I need to pass.

I don't really have a need to upgrade the power, but of course I will. Cause that's the what we do.

regards,
Leon

I know there are alot of opinions/suggestions out there. I think mine was the most cost effective with least labor. Here is what I did:
1957 235. dual carbs. bone stock 3 on tree transmission. All I did was change the ring and pinion gear in the rear end (Yukon gears). I now have a 3.38 rear and do highway speeds.(60-65mph) can do 70+ but RPM's get significantly higher once I push it past 65. here is the link for the gears: http://www.classicparts.com/1955-62-Rear-End-Gears-338-Ratio/productinfo/93-513/ GOOD LUCK

RPM's get significantly higher once I push it past 65

Not sure what you mean?
RPM is in direct proportion to MPH all the time with a manual transmission. A new axle ratio only changes the proportion.

Leon,
a 3.90 rearend running 215R75-15 tires with a straight 1:1 high gear will yield 2936 RPM at 60 mph. That is how the math works out. A typical tire of that size goes 753 revs per mile.

For what it's worth, the winner of the Special Turing class (stock sedans with less than ~250 cubic inches) in the 1953 Mexican Road Race was a stock 1954 Chevrolet with a Powerglide. This car averaged 77 mph for nearly 2,000 miles with what should have been a 3.55:1 rear end. 1953 Mexican Road Race results

I never heard what C.D. Evans did with the Chevy after the race.

Hoyt

Have you run a compression test, to verify the engine is up to par? I ran a 55 1st with a 235 for several years, and it got weaker and weaker. Finally ran a compression test which told me it was time for some attention. When I got the head off, I found 3 burnt ex valves, which meant that I was basically runnig on 3 cylinders. I ws still able do run at a decent speed on the freeway. After the rebuild, I put a 3:38 to one ring and pinion in it, and now I will be cruising down the freeway with the wife following me, and she will call me on the cel and tell me " Hey your doing 85 or 90. You better slow down or you're going to get a ticket." The 235 has plenty of power as long as it is in good shape, but as it wears and loses compression, it also loses power. A compression test is easy and will tell you alot.

235 is fine on the highway if you have the right set up. I agree with the posts here trans/gear ratio/ tire diameter make all the difference in the world. I have 51 Chevy Deluxe with 3 speed and enclosed drive shaft /4.11 gear. I can only do 60 with out the engine sounding like its blowing up. Now my friend who did the powerglide rearend swap (only one change) to a 3.35 rear gear can blow by at about 75 and get better gas mileage doing it.