These heads have the staggered valve cover bolts. They have bolt holes on the end of the head like Chevy started using in 1969. Wierd part is that the holes on the end of the head are only on one end The casting number is 3755548. Any help is appreciated!
I believe those are 57-62 283, commonly called the "industrial" head. Some were used in big trucks and industrial applications...Many ended up on 283s sold to Chris Craft. Do they also have a water crossover port on the end of the head?
Some of the early powerpack heads had the extra hole, I think for mounting the compressor on air suspension cars. But that casting number doesn't show up in my 59 chevy parts book, so I dont know what it's off of. what's the date code?
Checked through 4 different books,none list that no.casting at all,just 3755549 which is 58-59 283 truck. staggered bolt pattern. Might be some industrial engine or boat application.
Every '58 and '59 head I've seen had a boss cast on one end for the cars that used a compresser for the optional air suspension that Squirrel mentioned. When installed on the engine, one head looks "old" and the other looks like a '69 and newer head.
Thanks for the responses! There is no crossover port on the end of the head. When was the last year for the staggered valve cover pattern? Will look for the date code tomorrow - after the Gilmore museum show in Mich. Will also try to get a pic.
The bolt pattern on the valve covers was a mid-59 change. It seems like extra cooling holes were added to the block decks, and cylinder heads at the same time that the bolt pattern was changed.
The date code is D278 so that should make them born in 1958. In checking Ebay, there were several like looking heads and were advertised as 1959 Corvette heads. Did that vintage Corvette need bolt holes on the front of the drivers side head?
No, but since most Corvettes used the same "power pack" heads that passenger cars did, they got them as well.
no 59 corvette had holes in the end of the heads like later heads they are truck heads. not worth much unless you have a truck that needs them.
This is interesting and very confusing to me. There are 3755550 heads currently on Ebay and they are advertising them as Corvette and they are asking $1K. The same vendor in Ohio have several like heads that all have the mounting holes on one end of the head and they are advertising them as Corvette heads for 58 and 59. I thought I knew Chevy's pretty good but these heads have really made me scratch my head!
I sold one pair of 58-59 heads with the holes, went for five bills to a vette guy, I have another pair with the holes that is also listed in the 59 chevy parts book as being used on vettes and 4bbl passenger cars. Can you post some pics of the heads you have? including the ends, and the chamber, and the top where the casting numbers are? edit: correction: the heads had the boss, but not the holes....so yeah, the heads are probably for a truck.
My info has the 3755550 head as a 283 59 vette with staggered bolt pattern. It was a later in the year head and has a triangular (pyramid) symbol on the end. The head was an aftermarket replacement with a part number of 3758124 casting #s of 3760116 or 3755550. The pyramid mark is on the ends and internally also.
550 heads DID have the bosses and WERE used on some Corvettes, as well as power pack equipped passenger cars. Now, someone else can say that I'm wrong.
You are correct sir! 3755548 were a commercial 283 head found on large trucks and commercial vehicles (i.e. combines, farm equipment) Just a note: These industrial/farm engines had forged crank shafts and some came with magnetos.
1964-67 ChevyII and some light truck 283's had cast cranks. 3849847- 283 crank, forged steel/cast, main diameter 2.30", rod diameter 2.00", stroke 3.00" 3876764- 283 crank, forged steel/cast, main diameter 2.30", rod diameter 2.00", stroke 3.00" 3876768- 283 crank, forged steel/cast, main diameter 2.30", rod diameter 2.00", stroke 3.00"
Heathen, I won't tell you you're wrong, but my info says the only heads with bosses and 3/8-16 holes that you would find on a '58/'59 corvette were replacement heads. I'm guessing that Chevy figured since the 550 castings were the same ports, chambers, etc. whether they were used on a Vette, Car, or a Truck, they only sold the truck heads over the counter for replacements. Not sure what the NCRS would rule, but the 550 heads on ebay right now are not original equipment Corvette heads. And I welcome any documentation to prove me wrong. That would expand my possibilities for heads for my '59. I can think of no accessories on a Vette that would use those holes on a Straight Axle Corvette. Also not sure where else the crossover (3 holes, 1/4-20, water hole, 1/4-20, no bosses) was used, but ChrisCraft smallblocks used them. My 2 cents, Dan
I've been holding on to some heads like these for years, I was told they were 50s corvette, and they've got the d-shaped vette chamber. #3755548. No accessory bolts, no bosses. I had some 3755549's that had the powerpack witch-hat, but these castings are a rounded hat. Staggered cover bolts.
I'm only finding one casting number that starts with 89 1968 8917291 350 1.94 1.5000 64 Off the Nasty 28 site which is pretty damned accurate. I can find a 3998920 which is a 72 350. Eye exam in order maybe? http://www.1968ss.com/SBheadnumbers.asp
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