Ok, I almost feel embarassed asking what should be a simple noob question, but I'm confused so here goes.
I bought a 318 and trans out of a buddies car and I'm trying to find out what it came out of. Based on the casting number(s), I'm guessing a 1987 ish pickup or van.
The block casting # is 4387580 318 7 and the casting date is 8-28-86 as best as I can tell. It has a flat tappet cam and the "302" head castings. The stamping on the block by the timing cover is : 31809041220.

So now part two of my question. I want to go through this engine and freshen it up before I drop it into my Dart. I always thought most 318 (LA) engines were pretty much the same with a few exceptions such as cam and compression. When I try to look up an overhaul kit at Summit for example there are at least a half dozen different overhaul kits (not including differneces based on over or undersize components)for the 318 for 1970 through the late 80's. To bring this question full circle, what is the difference in the kits? Why cant I buy an overhaul kit (pistons, gaskets, rings and brearings) for a '71 318 and use it in my 1987 (?) 318?
Just for kicks here is the engine in question
Just wondering, thanks for looking
Scott

Short answer: you can.

Long answer: Why would you want to?

One thing holding most 318s back is COMPRESSION. The early '70s 318s used pistons with compression height of around 1.720, leaving the piston way down in the cylinder.

Your '87 motor should have pistons with compression height of 1.745, and the block deck is something like 9.578, leaving the piston something like 0.055 down in the hole.
I have such an engine and spent some extra $ to buy the thinner head gaskets and even so my compression is less than 9:1. If I were buying new pistons I'd look at early Mag pistons at 1.755" compression height, and use those, the 302 heads and the thin head gasket and get some compression going.

Of course, the real answer is the KB pistons that will get to zero deck or real close, but they are light enough that you'll want to rebalance the assembly. But then you could use a 0.040" head gasket and still be around 9.5:1, ideal for pump gas in that engine.

I'd strongly suggest you look at the motor you have and decide whether you NEED new pistons, my Fifth Ave. motor with 100K miles didn't even have a ridge in the cylinders. I'm reusing the stock pistons. Shoot, the crank didn't even need to be ground!

R.

Thanks Dogdays,
I guess I thought the compression was higher in 1971, but you are correct it was only 8.8:1 so I am probably better off with my original pistons if they are in good shape. I also agree that I'm not buying anything until I check it out and verify the condition and sizes of everything I have
I'm still wondering though why so many different engine kits, are the gaskets different between years or something?
I would also like to know what my engine actually is out of. Here is a pic of the block stamping on the front by the head

Well,, the part of that engine ID number that would actually tell me what year it came out of is on the left side under whatever that bumpy stuff is.

Basically it's the same engine whether it comes out of a Fifth Ave, a pickup or a van. That number should start out either 7M318, built for a 1987 model year car. The M stands for Mounds Road engine plant.

R.

Butbutbut...flat-tappet cam? with 302 heads!
There is just so much horsepoop floating around about this time period, it's hard to separate the truth from the other stuff. By 1987, four-barrel 318s were being produced mostly for police use. They had a 4-barrel carb, the 360 heads, but used the flat tappet 318 camshaft with 181/191 degrees at 50 lift. Only 318s got the 302 heads and those had hydraulic roller lifters and 2-barrel carbs. But with Mopar, never say never!