4.3 mercury to 4.3 Vortec swap

Hello, I have an older 4.3 carb v6 mercury and I can't find the bolt pattern so I can't compare it to the newer blazer 4.3 Vortec if anyone knows anything I'd appreciate the help.

 

I am assuming that you are referring to the bell housing interface?

I would call Trans Dapt Adapters, They used to make adapters for various engine to tranny set ups. If they don't have it the should know
Also a good bet is to call the auto wreckers, these guys normally know more than what one would think

You did not really explain if it is matching an out-drive or transmission etc.
The other thing to consider, even if if the bell housing pattern is the same is that
you need to know if the spacing is the same from the back of the bell housing to the
flywheel/starter ring

 

what year 4.3 are you removing?

 

If you are using an automotive engine, first check if it is internally or externally balanced. Externally balanced engines need a matched flywheel.