trying to find a replacement block

[seaswirl90]

hey! I am in need of some tips/advice. I have a 1990 18' seaswirl with a 4.3L omc cobra V6, 2bbl. The boat is in amazing shape but the engine's bottom end has failed. I have a new top end (including heads, and timing chain) and the cam and roller lifters are good but I need a replacement short block. I'd love to just take a vortec 4.3 out of an s-10 or blazer and convert it but I'm having issues figuring out what vintage block/truck I should be lookin for. can anyone help me or has anyone been through this and knows a better way???

 

[Scott Danforth]

1990 if you want the same

 

[hemi rt]

Get a 1990 Truck engine and you should be good to go.

 

[bruceb58]

If you go with a block that is 96 or newer, you will get Vortec heads, You would then just have to get a new intake manifold. This would be my first choice. You may have to add an electric fuel pump too.

Between 92 and 95 the engines were the same as yours except they have the balance shaft added which also requires a new intake manifold.

91 and older are the exact engine as you have. My last choice.

 

[Bondo]

I'd love to just take a vortec 4.3 out of an s-10 or blazer and convert it but I'm having issues figuring out what vintage block/truck I should be lookin for.

Ayuh,.... Welcome Aboard,.... Vortec heads came out in '96, so a '96 or later,....