I read somewhere on the forum where someone posted that there were 283's in '56 Corvettes, but now I cannot find where the post was. Anyway, to set the record straight, I built a number of 265's and 283's back in the fifties and sixties, and I had no recall of a 283 in any '56 car. So that I had accurate information, I contacted the Chevrolet Archive division, and they sent me 21 pages of every possible detail involving the '56 Corvette, including all options. There were no options for 283's in '56. All '56 Corvettes had 265's. I did learn, however, that in '56, the 265 was offered with two solid lifter camshafts with dual point ignitions and dual four barrels.. Both were dyno tested with this result. The 270hp cam put out 270hp at 3200 rpm's. I was amazed that the rpm's were that low. The 225 hp cam engine put out 225 hp at 5200 rpm's. I always believed that the engine known by the nickname of the "Factory 270" was a 283 introduced in the Corvette in '58. It put out the same hp as the '56 265 with the same aspiration and ignition, but I believe it had four bolt mains. How the 283 put out the same hp as the 265 is a bit puzzling. Also puzzling is how the '56 265 stayed together with all that horsepower. As I am sure you all know, the 265 was the early engine in '57, but it was the 283 block and was quickly punched out to 283. My third engine was a '57 265, and I know that for a fact because I had the spec's and mic'ed it before I laid out the bucks. I put the '58 225 horse (although it was advertised at the time as a 220 hp cam) ,with the dual point ignition, a high volume fuel pump and high compression heads and three Rochester two barrels on it. I had it put on a dyno, and was astounded that it put out 305 hp. Some things are just inexplicable.

 

A short addition to my post about the 283's in '56 Corvettes. I said the "Factory 270" was introduced in'58. But since the engine was introduced in the '56 in the 265, logically the Factory 270 may have been offered in the '57 283, but do not know that for sure. I do know that the Factory 270 was offered in a limited number of '57 two door hardtops, and I knew two guys who had them, and they were not transplants. So the '57 Corvettes must have had them. It would be interesting to know if the Corvettes in '57 had 283's before the passenger cars went from 265 to 283.

 

Sorry, I don't mean to beat this topic to death nor do I want to disparage the post that I cited, I just want to be credible. I just got an e-mail from GM's Archivist, and he said "No" to my query about the 283's in a '56. Just 57-61 for the 283's.I will not bring this up again.

 

Thanks for the history lesson. Good info. Was there a reason you put it in the C6 section instead of the C1 section? If not, I can move it for you.

 

I was only in the C-6 forum and the new member forum as far as I know. I searched all the forums with no result, so the whereabouts of the post I cited is a mystery, but it was definitely there. Since I have a C-6 Corvette, I just posted it here, hoping whomever posted the info about '56 Corvettes having 283's would stumble onto it. Feel free to move it where ever you want. It was a history lesson for me too. I worked on a lot of 265's, but never knew they offered that super power package before '58. You learn something every day, I guess, but I was happy that I contacted the GM archivist and got the 21 pages of specs which are available to anyone who asks, just in case someone is fortunate enough to have a '56. At age 18, I was offered one with a transplanted 283 punched out to 301 with the dual four barrel set up. The 301 could be an awesome engine with that short stroke and and big bore. They red-lined about 8500. I took it for a test drive, but thought it was over priced at $1500. OMG!!! If we could only look into the future. I am also a gun collector, and once I buy a gun , I never sell it, which is why I have 60 of them. I think the same policy should apply to Corvettes. Once you buy one, keep it forever, even if you up grade. I just pulled over a guy in a 2000 Corvette today, although he thought I was chasing him with my truck. I finally had to corner him in a drive-through and he was seriously pissed off until I started raving about his car. It was perfect in every respect, very tastefully dressed, in impeccable condition, and one of the most all around beautiful cars in every respect WOW!!!! I thought mine looked nice, but now I AM SERIOUSLY DEPRESSED. I am also a retired English teacher , which is why I cannot stop talking. Maybe you noticed that. One other thing. He showed me an adjustable chip that he bought relatively cheaply. It could be adjusted for economy or for added hp. It supposedly could add 60 hp to his motor. Anyone have the info on this? If I could add 60hp, I would be right at 500 in my LS-2., and that would be kinda cool.

 

I remember in the mid 50's that the passenger car had a 265 option that was called a Power Pack. I think it consisted of a different cam, 4 barrel, and maybe higher compression heads. I don't recall what the gross horsepower rating was on it however.
My fraternity brother roommate had a 56 Bel Air with that option and a 3 speed with overdrive. It was very quick.

 

Hi Shark. I never owned a '56 car of any kind, but I do remember people talking about the "Power Pack" engine, so I think you are right. I will give the specs on the '56 Corvette engines, but I don't know if any of those translate to a passenger car. GM offered 5 different engines in the '56 Corvettes: The FG at 225hp, the FK at 210 hp (which was the base engine), the GR at 225hp, the GU at 240 hp, and the GV at 220 hp. All carbs were Carters. All dual four barrel engines had a cast aluminum intake manifold and a very slightly improved exhaust system, but still a single pipe. The base engines had the stamped sheet metal valve covers with "Chevrolet" written on top. (And they all leaked!) All optional engines had the much stiffer nine fin cast alloy valve covers with "Corvette" integrated into the casting. They, when clean, were fairly bright silver and with an improved mounting system, never leaked. There is no mention of a "Power Pack" engine in the Corvette specs, but that does not mean that the "Power Pack" was not available in a passenger car.

None of the '56 Corvettes has four speeds; it was either a three speed or an automatic. The FK was the base engine with 210 hp and a three speed.

The RPO449 engine with an unspecified high lift cam came with the dual four barrels. Chevrolet recommended this set up for racing only and did not specify the hp. It was generally accepted that the RPO449 put out 240 hp.

If I had to guess, I would say that the passenger car with the "Power Pack"engine was either the GR or the GV with a solid lifter cam and high compression heads. With the four barrel, it would, indeed, be quick for a passenger car.

All of the engines, 265's and 283's had,of course, casting marks on the front of the heads. If the casting mark was flat all the way across, it had low compression heads and flat pistons. If the mark had a little arrow pointing up in the center, it had high compression heads and most likely notched pistons so the pistons did not hit the valves. The Factory 270 283's had a straight up narrow pillar pointing up in the center of the casting mark, which indicated even higher compression heads, the 270 hp cam, dual point ignition, and the dual four barrels. If you opened the hood on one of those, you knew immediately what you were looking at. If you want to get info on passenger cars, call the GM Archive people at 1-206-744-9340, extension 163. Ask for the specs on the '56 passenger cars, leave your e-mail, and they will get back to you the same day. If that does not work, go to the GM website, click on "Information" send them an e-mail, and they will send you the whole manual for the whatever you ask for.

About half of the info above came from the 21 pages the archive people sent to me. The other half is what I remember from those days. It is interesting how some things get embedded in your memory. At age 72, I can barely remember what I did two days ago, but after 66 years, I could still rattle off the firing order of a Chevy V-8.18436572 (I hope that's right! YUK- YUK.) Maybe I shouldn't have said that!!!

 

I've got you by 3 years and I can't even remember what I had for breakfast. Thanks for the info. When I get some time I'll give them a call and see if they can shed any light on the power pack. Pretty sure it was just for passenger cars from my recollection.

 

Man, I figured I was the oldest guy here. I will look forward to your communication on the Power Pack.

 

Pretty much told you everything I can remember about the power pack option. I do remember it also in addition to what I mentioned before it came with dual exhaust.