Cadmaro

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After some research, I was expecting to see a casting number ending with 416 when I took the valve cover off of my 1985 trans am but instead I have 462624. Trying to run the numbers online I found one place that says it is a 76cc head from the 70s and another says it is a 305 head from the early 80s. After some digging around it appears that my engine is grey but my intake manifold is grey on told of blue/silver and there is rtv around all the gasket surfaces Any clue what engine might be in my car?

Cadmaro

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8t2 z-chev

'624s were used on 1979-86 350s,corvettes to pickup trucks-76 cc,usually 1.94/1.50 valves.they flow quite well when correctly ported,but like to run hot between the center exhaust valves,crack and warp.very similar to the earlier '882 heads...
350 blocks 1980-85 will often have a large "207" cast into the side.New Replacement "target master"engines also used a version of '624 heads
also the blue color seen on the aluminum intake would indicate that part is '81-82 era,earlier intakes were iron.

Cadmaro

iTrader: (1)

So does that mean that I may have a smog era 350 instead of the lg4 I was expecting? Seems like a 76cc head on a 305 wouldn't even make 8:1 compression and should barely run. I'm adding a pic of the paint on the intake (which is aluminum) and the valve cover that matches the block and heads

sofakingdom

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Your heads have date code D288. That code says they were cast (not necessarily that the engine they came on was built, just, they were cast) on the 28th day of the Dth month (the 4th, April), of a year ending in 8. That would be 78 in this case. Most likely source would probably be a truck, as most cars by that time had 305s. Most, but by no means all... I'm talking "likely" here, not something absolute. That would be the 76cc smogger crap from the 70s.

They are GARBAGE. I can think of FEW castings I would more AVOID if building a motor I wanted to run good, than 624. However if you're happy with the way it runs, that's all that matters; my opinion isn't a factor in your satisfaction.

You have a Small Block Chevy. Don't even need the RTV to tell us that. Could be: 262.5, 265, 267, 283, 302, 305, 307, 327, 350, or 400 if stock; or, any of a vast combination of other sizes if it's not. 383 for example.

Get the block casting #. That will tell you what the bore dia is. Won't tell you what size THE ENGINE is; for example, a 4.000" block originally, might now be a 302, 327, or 350 if stock (or it might have slightly more CID if it's been bored out, as is likely); or it might be a 383 (not as likely but not impossible). Most likely, if it's a 4" block, it's some overbore of a 350. A 350 still, but with slightly more CID due to the "maintenance" performed on the block.

A 305 with 624 heads would indeed have very low compression. It might run fine, especially with a very small cam; it would make good torque on premium gas, but have very limited RPM capability. OK around town but very gutless on the freeway. It's not at all impossible, or even very unlikely, that that's what you have. People build some truly HEINOUS combinations sometimes, for reasons none of us who come behind them can fathom. Or for no reason at all sometimes... they just … do.

Ignore the paint colors. All they tell you about the motor is, what the can of paint the person who used on it, was holding. It tells you NOTHING WHATSOEVER about "the engine" proper. Not the CID, not where the intake came from, not the age, not ANYTHING. Anybody can paint any motor any color they want any time they want for any reason that seems good to them, or for no reason at all. About all that a strange paint color tells you is that someone has had his d***-skinners in there. In this case, the blue color on the intake most likely tells you that the paint in the can that the person squirting it was holding, was blue. While not impossible (again, we're dealing with "likely" here) the bue paint probably didn't come from GM. Might have; but not as likely as, whoever painted it liked, or just happened to have on hand a can of, blue.

Cadmaro

iTrader: (1)

Fair enough. I understand that without disassembly there is know way to have a concrete answer as to what it is. The car is slow (to me anyways) but still feels better than I expected 160hp would in a 3200lb car. Guess I'll just see if I can read the casting number on the block before I decide which direction to go to achieve my performance goals.

Cadmaro

iTrader: (1)

Block casting number is 14010207 so it looks like it is some iteration of a 4" bore engine
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dmccain

iTrader: (2)

Dad bought an old Coupe once with supposedly a reman crate engine. Thing ran decent too. When it got to smoking we found it had a 601 58cc. Head on one side and I believe an 882 76cc Head on the other side. You just never know. We stuck a set of 059 58cc Vortecs on a 350 several years back and it ran very strong.

sofakingdom

iTrader: (1)

Yup, 207 is a early/mid 80s 4" block. So, probably a 350. More likely than anything else anyway.

Cadmaro

iTrader: (1)

Luckily mine a has the same casting number head on each side. Lol