Re: Cracked block at head bolt hole in my 470
i am in the process of rebuilding a 470, It is a really interesting motor, lots of topics about it. I too was thinking of swap options. As i read more and more i was really bummed about the design issues, that are sure to effect the engine, especially the cam seal issue. As i got mine apart i found on cylinder head was badly pitted due to water in the block. In my case the out drive water pump was not working and the engine overheated, i believe making the head gasket leak. The head on mine was so badly rusted i had to cut off one of the bolts. I felt like giving up on the engine several times, i am replacing all stringers, transom and deck From what i have learned swapping to a 4.3 v6 is the best swap, you will have to redesign and glass in new motor mounts. the 470 usually uses a single large block to bolt in where the 4.3 will need 2 mounts on the side of the engine bay. to get the mounts right you would need to bolt up the rear of the engine align the out drive and then measure the engine mounts, then take the engine out and glass in the new mounts. You also may have to modify the dog house. Shifter/throttle cables may also require some mods. As i read more, there are some good things about the 470 but it takes special care. the aluminum block is quite advanced for its time, and it is a huge 4 cylinder, that is lightweight and gets decent gas mileage. I have decided to stick with the 470, add the alternator kit and repair my cam seal issue, mine did not leak past the second seal but did cut a grove in the cam on the first seal. This is the first engine i have ever worked on, and i had to buy a lot of tools to do it. feel free to PM me if you want to talk directly, i am learning to like the engine despite all the know issues. Of course i may regret that decision. I found a new block and head from a working engine that was burning oil, i am going to try to combine the two, get new rings and hone the new block. I will do a full inspection of the crank shaft as well. gasket kits are not to cheep, they run around 200 i think. There seam to be a lot of blocks available out there but the key is to find one local from someone that knows a little bit about the history of the block, like was it running at all before it was removed and stored. my best advice is to take some time and review as many posts as you can about the engine. i have lots of pictures of the work i have done.