engine size

I just bought a 1978 correct craft with a ford v8 engine but im not sure if its a 302 0r a 351 is there a way to tell what size the eng is ? thanks for any help u guys or gals can give me . I haven't seen anything on the top of the eng that would tell me anything either .

thanks grand poobah the pics helped looks like a 302 in my boat . what do u think about welding a cracked block ? I know there is certain things to do to weld it im just wondering if it will last ?

Jeff, I feel your pain! Im in the process of restoring a 63 American skier that had an original 170 cu. in inline 6 Interceptor. (a more difficult motor to find parts for doesn't exist!) Anyhow, I knew of (1) external crack in the water jacket which did not get me immediately excited. As my tear down progressed I had the block hot tanked and (4) cracks were noted in the valley adjacent to the lifters.
So, I have a good friend who does very specialized repairs on large castings, locomotive motors etc. and he offered to give welding a shot. So he magnafluxed it once (no pressure test) and felt we had located everything so he took it for a couple of weeks and worked on it. Baked the block, welded it and sand mounded it for about three days until he got back to it. Anyhow it looked marvelous until the second maganaflux and a whole rash of cracks had opened up on the opposite side. Infuriating!
So, I'm with Gary get another block. Your in a much better position than I was there are ford v8 blocks everywhere. Get a bare block if your internals are in good shape. However remember you will have to have machine work done to keep swapped parts happy, I assume your engine is reverse rotation. This is not a bad thing. because there are a lot of good buys on craigslist that can be maranized, just check over what you are buying and plan on an overhaul.
It took me two months to find a 170 cu. in. Ford inline 6 block (comet engine). I finally found several and was surprised how difficult identifying that vintage of motor was. There were several variants and there were 200 cu. in. l6's ( as I discovered) that were 4 main bearings like my 170 cu. in lurking around and misidentified made just prior to the release of the 250 cu. in. engines that had 6 mains. I almost bought one until block stamps didn't match. So finally I got lucky, I got one with all identical stamps and a block casting code that was the same year and 2 months later in production I had to drive so far out in the middle of nowhere to get it my GPS wouldn't register!!
So good luck, finding another block is much less hair pulling!

Thanks for the help u guys have given me this is a great site glad I joined . What a story glass dog and it looks like ill be replacing the block in the tique , after pulling it yesterday I found a 3x3 hole on the back side of the engine . so my adventure begins lol .