Good morning everyone, I have a 1950 Chevrolet 3100 that I’ve owned since I was 12. My Dad and I “restored” it when I was 15, and it hasn’t been driven 3000 miles since. I want to start driving it more and so I started looking into Small Blocking it. I don’t mind the work, but there’s quite a bit involved, rear axle, steering gearbox, etc. Recently a thread came up about 261’s and it got me to thinking. My truck still has the Babbitt Banger 216 and it is very tired and I was thinking about a full pressure 235 or 261. I’ve found a few later model 235’s on eBay. I really don’t know anything about the 235. From what I understand, this would be a much more straightforward swap than a SBC. What year did the full pressure engine start? Speedway has headers and intakes, are two carbs worth the effort? Does anyone still make hotter cams for the 235? I’m obviously not looking for a screamer, just a warmed up dependable driver. I’m also not opposed to putting 3.55’s in the rear axle (4.11 currently). Thanks so much, you guys are always so helpful!
You don't have to change the steering box with a small block, Chevy had so many different exhaust manifolds you can get by without changing the box.
235's are good engines, bolt in. I had 54 Chevy truck with two one bbls on it and split exhaust manifold, ran great.
The full pressure 235" with solid lifters came about in 1954, with the manual trans. Powerglide 235" engines were full pressure a couple of year before that, and were hydraulic lifters. I have owned my '54 3100 for 30yrs. with the granny low and stock 235". Never had any troubles with it. Drove it every day for 10yrs, even with Denver weather. Lots of info on the web and here to help you decide how you want to go.
235 full pressure oiling to rods and mains started in 53 but only on Powerglide equipped cars. All 54 thru 62 were full pressure oiling. Differences in water pump and pulleys 55 on. 261 was in trucks only in the US but used in Pontiacs in Canada. The 261 cam is an upgrade for 235s or lots of aftermarket versions. Dual exhaust provide some performance improvement and sound great! Dual carbs also, but are more complex to set up. I'm more in favor of a larger single carb on a modified manifold. Milling the head for some added compression is a good idea and probably the most bang for the buck. Some 261 had not only full pressure oiling but a full flow oil filter rather than the bypass used by 216s and 235s. Identifiable by the 1/2pipe thread ports in the oil passages on the left side of the block. Those are the best IMO, but not enough better to delay the upgrade looking for one. Grab the first 235 you find and do the swap! You'll be happy with the result.
This point probably deserves a bit more explanation. The "short" water pump was used through 54, and the "long" pump started in 55. The big difference is how the block is cast, the short pump has two water passage holes in the front of the block, and the pump bolts to the surface of the block. The long one has a single large round hole in the block, and the pump fits into the hole. You can modify the long pump to be shorter, it takes a little effort to get the right pulley, press the hub, shorten the shaft, etc. Or get an adapter to mount the short pump to the later block (it's just a steel plate). Or move the radiator forward to make room for the longer pump. You'll have to deal with it somehow, the best way of course is to find a 1954 engine. I'd be tempted to see about doing a quick overhaul of the 216, but of course that depends on the condition of the crank and rods. It could be that they're worn out, as you say, and it could get expensive to fix. Or maybe not too expensive, if you can get the crank reground and find some rods to fit it. You also have to see how much wear is in the bores. When I was a kid, I did an overhaul on the babbit 235 in the neighbor's 53 Chevy car, it ran pretty well after that. But it might not have led the harder life of a truck engine.
For a sbc you could use a iron truck bell to bolt to the original trans. You’d lose the foot pedal starter. The 235/261 is simple. Just got to figure out the water pump. Tons on info out there.
I have done a bunch of these swaps.For the 55 and newer 235/261 the water pump adapter plate is best, raises the fan up about 3 inches and back an inch ....Better cooling at low speeds..but...you should retain the stock pulley ratio of the 216..I always looked for the right pulleys..Cant say what other guys use or if pulley ratio actually matters
Also be aware of the fan blade situation; when I put a '58 235 in a '53 car, once I moved the water pump hub and found a suitable pulley for it, the '58 fan blade was too large (would have hit the upper radiator hose), and the '53 fan blade was a smaller bolt pattern.
For reference...I was just talking to my brother yesterday about a 54 235 sitting in his garage that he needs to find a new owner for. He bought it as a spare for his 54 Belair that he no longer has. Pretty sure it is a good running engine. But, appears it is about 8 hours from you in the Detroit area.
If you want to spend more time driving than wrenching, go the 235/261 route, I'd be happy with either choice. My '51 3100 has a 327 (which I LOVE) but this swap usually gets into 'project creep' mode and takes the rig out of service for a much longer time than an engine swap. You might want to start with the engine swap, then after you have it 'debugged', change rear end gears. Good luck!
I think the effort it would take to swap gears, plus the cost, into your current rear, I’d be looking at doing an open drive conversion, even if going to a 235. I think the track width is the same for a TF truck, so if wanting to stay 6 lug, and if still available, GMC through the 60’s offered more ratios than Chevy did as I recall. I’m just basing the track width off the front axle though, my recollection is the king pin width was the same, just the spring pads were narrower on the AD trucks.
Located a 55 AD rear It’s open. Mine is already open, using a 6 lug Dana 44 from a c10. The other rear comes with a front axle. I’d like to get rid of my huck brakes. If my scrap yard hasn’t shredded it, they have a 54 belair with a pg. all the driveline is intact.
Here's a free one just posted on the fb 1956. You'll have to look it up, or send me a PM and I'll pass it along. In Twin Cities Minnesota. edit: He says it runs good, trans too but leaks. Came out for a V8 swap.
A water pump adapter is made to use the 54 on back pumps on the 55 and newer engines,I have installed two and two holes need to be drilled in the block which is easy to do. A guy on the Stovebolt page makes them and also sells them on ebay and I think goes by pre 67 dave,might be available through other vendors too.
Years back like almost 60...LOL...I put a 54 235 six in my 37 and for the most part it was a bolt in job....Think I had to drill the holes for the 37 engine mounts to the 54 motor...
Guys, thanks so much for all of the great information. This is going to make a great project for Little Truckdoctor and I. We expect to get started on it in the spring. I hope to start a build thread on it when we get going.
235 is great engine. Sounds good, looks good, won't disappoint you unless you want to get silly. A 5 speed would be a great addition.
I had a 235 in my 1957 Chevy pickup for a while. It is a great engine, seems like they start and run regardless of malady. Then I put a 261 in (dual carbs, exhaust, etc.), it was practically a bolt-in swap, minimal fuss (short water pump required if memory serves). I would recommend going directly to the 261, same amount of work, improved results in my opinion. Also check here for info: https://www.stovebolt.com/techtips/ don