A buddy of mine is restoring a chevelle(72 i think). He is not going to be using the motor that came with the car when he bought it. The previous owner told him it was a 350, but when my buddy looked at it the markings pointed to it being a 305.

My question is, he offered to sell it to me pretty cheap(~$200), is there a way that i can tell if its actually a 350? I dont really need another 305 in the SS. Id like to put a 350 in there and eventually get about 350hp at the wheels(reasonable number from what ive read with some work)

on the passenger's side behind the head, on the block u will find a casting number that u can go to mortec and find out what it is. on some blocks it says on the driver's side it may say the CID or just 5.0L, 5.7L in small letters

here is a pic of mine

My buddy said he looked up the numbers and it said it was a 305. Can a 305 be modified to a 350 with ne parts? I was told the only difference was the heads?

No, it can't. The bore of the cylinder of the 305 is smaller, and there is not enough metal to bore it out to 4.00 inches. Pretty much all of the other parts on a 305 can be swapped to a 350, but the heads for a 305 are pretty small for a 350, and in some cases can raise the Compression Level too high for comfortable street operation. You can bore and stroke a 305 to about 335, but the cost of that is way more than buying a good 350 to start.

Ok so if i understand correctly, if the block has markings that say it is a 305, there is no way it was built into a 350. Is that the proper assumption?

Its a buddy of mine from high school, so i know hes not trying to pull the wool over my eyes, but who knows if the previous owner fed him some BS line about it being a 350.

You're right. There's no way it's a 350ci engine from a 305ci block. There'd a pretty happy 305 crowd if it could be done.

I think the closest you can get is like 335ci or something. That's bored out and stroked. Smart engine guys like SS402 or someone can chime in and let you know for sure how big a 305ci can get.

hmmm....ok, good to know. From what ive been reading it seems like i could possibly attain about 350whp from a 305 with some work though correct?

Maybe its still worth getting the motor even if its a 305 so i can build it up and then just drop it in.

Thoughts?

.. an overstroked 400 crank might be able to be shoehorned in a bored 305 block, giving about a 350, but that isn't likely... or the block could be bored and sleeved to a 350... but neither of those is very likely... just get the block numbers and we can double check on the size...

.. 305's are about as common as 350's and cheaper, so someone may have swapped a 305 in the Chevelle...

.. A mild performance cam, headers, and free-flowing exhaust can give a nice boost in usable rear wheel power to the 305"... knock a couple seconds off the 1/4 time... very noticable seat of the pants... all transferable to a 350 later...

.. an overstroked 400 crank might be able to be shoehorned in a bored 305 block, giving about a 350, but that isn't likely... or the block could be bored and sleeved to a 350... but neither of those is very likely... just get the block numbers and we can double check on the size...

.. 305's are about as common as 350's and cheaper, so someone may have swapped a 305 into the Chevelle...

.. A mild performance cam, headers, and free-flowing exhaust can give a nice boost in usable rear wheel power to the 305"... knock a couple seconds off the 1/4 time... very noticable seat of the pants... all transferable to a 350 later...

.. In any event, all is not lost, if you're willing to part with $200, you can prolly find a used 350 lots of places...