I have a casting number on rear of engine GM 3056180, what is it? Also a clock looking face with 12 64, and on front of left head TIII 7 HC. What do these tell me??

you would have to get the foundry bill of material for that crankshaft
finding the casting foundry will be a job in itself
however crank shafts are cast to a engineering standard (throw distance) and are then ground to a standard size on the big ends and main journals
what ever con rods that are used depends on the block that the crank shaft is installed in as different piston diameters require different strength conrods
the casting number is just a batch number so it may prove a dead end if you are relying on it to get information
where I would start looking is at a engineering shop that regrinds crank shafts as they may have original specs for gm cranks and that number just may indicate what block it was made for and then you may get a heading as to where to look

The rotor button should be pointed at the number one cylinder on the contact of the distributor cap. Be careful because on some of the GM distributor caps can be a little confusing. The contacts on the inside of the distributor cap can sometimes be a little confusing. Also on another note, those 5.7 vortec heads on a older 5.7 TBI block will make a very noticeable difference. Make sure and check the exhaust and intake ports and see if they are the same size. Some vortec heads have what they call a "Cathedral port". Lastly if you are kinda handy around a shop you can port and polish the inside of the cylinder head yourself. The main thing is to get all of the rough casting burs off the inside of the ports. I have used a flex head dremel tool and sanded them smooth. You will not believe the increase in torque, horsepower, and throttle response. Good luck.

You will have to find the casting number on the block, heads, and intake to see if all those are original to that motor, but the block casting number will tell you what year it was made, and the types of vehicles it was used in. It might be difficult to pinpoint exactly what it was in originally if they used it in more than one type car, or produced it more that one year. You can google up a site that will help you find the block casting and decode it for you. Just type in GM engine block decoder

153624 is possibly the firing order but the numbering of the cylinders ? never seen one so i wouldnt know sorry their out engines here in europe only use 4 cylinders and the newer ones 3 cylinders try 143625 if the first firing order doesnt work ,i would expect no 1 to the front left but i just dont know i could work it out with head under the bonnet and follow the rockers working out the timing but offhand no idea

site i use for casting numbers is down at the moment
far as if a camaro motor would work in your truck yes small blocks between trucks and cars the same
there are 2- bolt main blocks
and there are 4-bolt main blocks
2 and 4 bolts are used in cars
and 2 and 4 bolts are used in trucks
main differance between truck motors and car motors are the add ons intake exhaust manifolds
heads the blocks them self are the same
trucks are usally geared lower but that in the tranny and rear end not in the motor
soon as my site comes back up i look up your number for u and give u link to site as well

the block casting when you are looking at the rear of the engine would be where the bellhousing bolts to the engine on the top-left side of the engine, the head casting should be on the left side head when looking from the back torwards the middle-bottom,and the crank cast should be behind the flywheel on the engine

Some where on the intake there will be the firing order cast into the intake. Just remember passenger is 1-4 and the drivers side is 5-8. If not I think on the sticker it will tell you the firing order. Make sure to gap the plugs.