How can I tell if I have a 350 or a 307 in my 69 malibu by looking at it? The old door stickers are gone. The engine is chevy orange like a 350, but I think all the small blocks came that color. It has a two barrel carb on it with a little chevy sticker on the passenger side of the engine.

Get the Engine ID Number as shown top right

http://www.yearone.com/updatedsinglepages/Id_info/gm_engine_id/gmidimages/endinedetail1.jpg

Get the Engine ID Number as shown top right

http://www.yearone.com/updatedsinglepages/Id_info/gm_engine_id/gmidimages/endinedetail1.jpg

Then visit here to ID:

http://www.mortec.com/

Also you can look at the engine mounts. The 307 was the only sbc that didnt have a interference lock on the mount to keep it from coming apart if the rubber fails.
Bill

but mounts go bad and get replaced fairly often.
one thingto look at is the balancer on the front of the crank- a 307 has a thin balancer that is the same 6.75" diameter as most 350 balancers, but is only about an inch thick at the outside diameter, where the 350 balancer is closer to 2" thick. this, too, isn't fool proof, since balancers do get changed out from time to time.
if you can't find the engine id number on the front pad, then look for the block casting number or pull a valve cover and get a head casting number and go to www.mortec.com and see what the numbers come up as.

The alpha letters at the end of the long VIN number string that should be on the block at the top right of the pic will decode to tell us what you have if you want to post them.

pdq67

but mounts go bad and get replaced fairly often.
one thingto look at is the balancer on the front of the crank- a 307 has a thin balancer that is the same 6.75" diameter as most 350 balancers, but is only about an inch thick at the outside diameter, where the 350 balancer is closer to 2" thick. this, too, isn't fool proof, since balancers do get changed out from time to time.
if you can't find the engine id number on the front pad, then look for the block casting number or pull a valve cover and get a head casting number and go to www.mortec.com and see what the numbers come up as.

Thats true, especially 307 mounts!

MY EARLY 350SS had stock 6-banger mounts on it so tell me about it!!

I ended up bolting both broken halves together on both and never had a problem again!!

pdq67

307 block casting numbers:
3970020, 3914635, 3932371, 3932373, 391436

350 block casting numbers:
3970010, 3932386, 3932388, 3956618, 3970014, 14010207, 14010209,

If you are sure it is stock, and hasn't been tampered with, you can look at the carb. 307s used the small 2GC, while 350s had the larger 2GC. Airhorn flange and throttle blade size is different between the two.