I have recently found out that the guy who sold me my car lied about the engine being a 400 small block. Its a SBC #3970010 and I took my heads off to find it a nightmare after the machine shop. The heads that came off of it were 487's and I want to replace them because one is cracked and the other has problems everywhere. I wanted to know if 493's heads would fit my engine without any drilling or modification.

 

Using google and putting in 493 heads, I got the following site:
493 heads?

The block is a standard 350 block which is supposed to be decent. I have one in my blazer and it runs well.

 

yes it will fit, the 493's have a hair larger combustion chamber and larger exhaust valve , 487 specs are 75cc 1.94 1.50 and the 493 specs are 493 76cc 1.94 1.60

you can't always rely on what the seller says, sometimes they are even miss informed, like my budy bought a 74 blazer the guy said it had a 305 in it, long story short he pulled it was going to sell it guy fell trought and was destin for a scrap yard so i took it off his hands becuase i couldn't let a good running motor go that way and it ended up beign a 350 4 bolt

vortek heads are your best bet for factory head, they are by far the best ones from the factory, you would have to buy a different intake becuase they have a different bolt patern but in the end best bang for the buck

 

considering the 493 have the big exhaust valve might want to have the intake valves enlarged to the 2.02 valves. then again throwing money at those heads i think would be kind of a waste. big combustion chambers, pressed studs, small intake valve, and most probably bad flow numbers. the vortecs are the best cheap factory head, but are going to require a different manifold. at that point you can get a set of iron eagles or sportsmans and out flow them.