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Any suggestions on improving the performance of a stock 235 engine? Everything on 53 1/2 is stock would consider dual carbs or headers. Any suggestions? Thanks, Scott

Don't bother- - - -the cylinder head design is so primitive that it can't benefit from those kinds of modifications. Dual carbs and headers are just eye candy on a stovebolt unless you do very radical modifications that make it unreliable for street use. Even then, the gains are pretty modest. A 261 is a much better starting point, and modify for torque, not horsepower. Even with a 261, get ready to spend a wheelbarrow full of money for pretty minimal improvements in performance.
Jerry

If you want to bring a Stovebolt engine to life, buy a Carter YF2100 and T-5 transmission from a four cylinder S10. The extra gears are close together which results in the engine being in the optimal power range on every shift. You won't have to spool the engine all the way up to avoid lugging the engine down in the next higher gear. Overdrive in fifth gear is nice too.
The Carter carb does not have the infamous Rochester model B stumble on takeoff. These two mods make driving these trucks an absolute joy!
Carl

How much will an 848 cylinder help?
Jeffrey

If or when the head is off, mill .0625" off for a significant, economical improvement.

Ed

Why mill the head when the purpose of finding and using a 848 head is because those heads boost the compression ratio because they have a smaller sized combustion chamber. Jeffrey

scotts60,

You might want to specify the year of the 235 block you want to use in your 1953 truck.

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The "848" head was produced from 1956-1962 (it is quite common, and it works on any 18-head-bolt 235 block) and it resulted in higher compression. These heads seem to be prone to developing cracks. The "848" head can also be used on a modified 261 block

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A slightly higher lift cam was used on 261s and on many 235s, depending on the model/year/application of the 235. That cam be used in any high-pressure-oil-system 235.

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Do not overdo the carburetor(s). The simple-minded method of matching carb/carbs to a Stovebolt-6 engine is to match CFM ratings of carb/carbs and the engine. CFM is not a readily available parameter, so you could try to roughly match the cubic inches of the 235 engine and cubic inches of the engine that the carburetor(s) came out of.

As suggested in other posts above, you cannot easily/inexpensively get a lot of additional power out of a Stovebolt engine; but, you can get a noticeable improvement with careful changes.

It seems that many people get rough-running souped-up stovebolt-six-engines caused by adding "too much carburetion". For example: using two 235 carbs on a 235 or two 261 carbs on a 261. (I have first hand experience).

It also possible to have "too little carburetion", resulting in a fuel-starved poorer-performing engine (I have first-hand experience with Landon's dual Carter-Weber on an wide-bore 261).

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It does not look as cool as multiple carbs, but you could look for an appropriate-size two-barrel carburetor and/or a carburetor with adjustable main jet/jets. GMC Zenith Carburetors could be used - they are a little uncommon and they can be expensive (because they are rarer and quite good carburetors - making them worth more).

Jeffrey, Milling a head reduces the size of the combustion chamber, thus increasing the compression ratio.
The option of milling your current head may not guarantee the same performance as an 848 head. There may be differences in the shape of the 848 combustion chamber than what you will end up with a shaved earlier model head. Some have angle milled the head to reduce chamber volume while reducing how much metal needs to be removed.

Milling the earlier head enough to get the compression increase of the 848 will result in the intake valves hitting the pistons unless the valves are recessed into the head the same amount it's milled. That shrouds the valves and reduces volumetric efficiency. Just find an 848 head, get it reworked, and bolt it on.
Jerry

How much more prone to crack is the 848 head?

When looking for an exhaust manifold I scored a complete 235 from a 1958 Chevy Biscayne with 40,000 miles that was running fine when pulled to put a small block in.

This is how I now have an 848 head. Though we got it to late in the rebuild for the 54 235 to consider using it. Though it maybe nice to use when the next time the head has to come off or another rebuild has to be done. But that better not happen for many years to come.

Being the 848 has the smaller combustion chamber there is no need to cut the head. Having less metal is never the best option in my mind. I want long life.

Though my question was how much difference would using an 848 head on a 1946 or 1954 235 as increase in HP and MPG.

The amount of difference is needed to make the decision to use the 848 head. Jeffrey

Do you remember the thread not to long ago where a member had engine work done and a valve was hitting the piston. That was a good read. I believe you posted on it. Jeffrey

I got a '57 235 with an 848 head from an acquaintance and upon getting it rebuilt, the machine work for the valve seats cut into the water jacket just a tad (like a grain of rice sized hole) because the inside of the water jacket had corroded outward toward the valve seat area.

Got a whole 235 with an 848 head for $100, just for the head, which turned out to be cracked.

Got an offer from a local Inliners guy who was willing to sell me an 848 head, but only if it checked out good. It was also cracked.

That's my experience with them so far. Have kinda put my search on pause. I know a guy with several Stovebolts sitting around, but he's been too busy lately to really look into what he's got. Engine build is on hold for now.

Depending on where, and how bad the crack is, some heads can be repaired. When I was running the connecting rod department at a big machine shop in Nashville Tennessee, we did quite a bit of business with a repair facility called Diesel Cast Welding. Of course, it was probably cost-effective to repair heads on big Diesel rigs. Whether or not the repair cost would be worthwhile on a stovebolt head, I'm not sure.
Jerry