The Stovebolt Site Forums The Shop Area Engine Shop Frankenstein 235's - A confusing discovery

I've been quietly looking around for a while now and using the search button A LOT and have found a ton of usefull info here and on the net.

I'm in the deconstruction of my first reall frame-off resto and ran into some confusion when looking at the motor.

the truck is a 1954 3100 pick-up, by now I know that is by no means the way to tell what motor it has.

first thing I noticed out of place for a "54" motor is that it had the 2 center bolts holding down the valve cover. that was the red flag that this motor is not original and even worse, it is the low pressure ( less desirable from what i've read) engine.


But from what I have found, the casting number on the block says 1954 block. Where as the casting number on the head translates to 1953 head ( as expected with the 2 center bolts)

so I guess what my question is,

"can a head from the earlier 235's ( low pressure) be installed on a newer ( high pressure) 235?"

block casting number: 3835911
head casting number: 3701887
engine serial number?( on machined plate behind distributor) : T43C322

I have also read that the earlier 235's had a "taller" side cover with the spark plugs passing thru the cover. where the newer 235's have a "shorter" side cover, stopping below the spark plugs. My motor does indeed have the shorter side cover, so does this mean it is for sure a newer, high pressure block?

Thanks for the help!!

the head is from a 53 235, someone else will have more info.
http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1916-57cast.html

235s from 1950 onwards had the short side cover.

3835911 was used from 1953 through 1955-1st series.

The 2-bolt 1953 head is an "oddity" in that it has a bolt pattern that matches the later blocks (does your head have 18 head bolts)?

Here are the locations of the head and block date casting codes.

Maybe someone else can decode the engine serial number?

What kind of valve cover does your engine have? The reason that I ask is that the aftermarket aluminum valve covers are the earlier 2 bolt style. They come with studs that go thru 2 rocker arm supports and then extend up to hold the valve cover.

The 1953 235 heads were similar to heads used up to 1962. Since the valve cover used the two studs, the heads don't have the four bolt holes on the side lip. It is my impression that there is no reason to worry about your 54 motor having a 53 head as long as everything works properly including the oil supply to the rockers. That would be the way I would look at it.

Welcome Locogringo. I'm impressed that you used and found the Search feature. I know it's not too hot but we stillencourage it's use.

I think Greg H might be on to something with his thought about your having an aftermarket valve cover. As an example take a look at my engine photos for the 53' truck which definately has a 235 from a 55' car in it. This I know because I put it in there. It has a Wayne aluminmum cover that uses the two extension stubs on the rocker shaft blocks and illustrates what Greg is getting at.

If the 2-bolt cover is being used (with adapter bolts) on a 4-screw valve-cover head, take off the 2-bolt valve cover and look for the holes for the 4 side screws used on the newer head.

Or, better yet (and easier), post the date casting code.

Nonetheless, as garandboy posted above, 3701887 is a 1953 235 head casting code (2-bolt valve cover).

Looks like locogringo made a hit-and-run post?

Canadian trucks changed to a full pressure 235 part way through 53 and they had the 2 bolt valve cover.I have seen several of these motors and I have one in my shop.I'll try and dig out the head for the part no.There was recently a canadian 54 for sale on ebay in arizona with the 2 bolt stock valve cover, so you never know where they will show up.

Here's the story on the rarest head you can find and that's the 53 passenger car head for use with the powerglide trans and it is an odd ball but rare piece. The 53 235 with powerglide is the first full pressure motor and has the largest intake valves at 1 15/16" and has the two studs for the valve cover. These will interchange with all 235 and 261s up to 1962. So if you got a new 53 Chevy car with a stick shift you got splash oiling, with the automatic you got this full pressure head. Your head number 3701887 is correct for this head.

sorry guys, not a hit and run post. just get really busy with summer school, odd ball jobs to pay for tools and parts, and time to play with those tools and parts.

I got the date code off the motor today : CON 1 G 23 4

so that means July 23 1954 correct?

that takes care of my worrys of it being a "low pressure" motor.

as for the head, I will pull the valve cover to get the head date casting code next time I'm working. If it is this "rare" one JiMerit is talking about, is that a good thing with the 1 15/16 intake valves? even tho the block is 54

Just for S&J's :
I seen 2 guys argueeing about the placement of the date casting numbers, one saying his were BEHIND the starter, the other saying that no numbers are behind the starter but just above it. Mine were BEHIND the starter, with the starter on it was impossible to read the numbers. now I do not know if the starter is original so it my be bigger than the original starter, thus covering the numbers.

yall sayin I hit-and-run post.

yall did a reply-and-run. lol

just wonderin if the head with larger intake valves is better in any way, or should I find a normal '54 head for the '54 block.

and conformation on it being a "full oiler"

A 1954 block date casting code indicates that it is 1954 high-pressure 235 block.

It's a matter of choice regarding your interest in having a "matching" 1954 head. I'd bet that a significant number of people with 235s do not have "matching" heads and blocks.

Someone else will have to comment on valve differences.