I have a 1986 Dodge Ram Van B150 3.7ltr 225 1barrel carb.
this van has duel Cats and both have been emptied out and both have holes in them.

they are small holes but there are many.
would this cause a lack in power espeacialy
sence the cats are right out of the manifold.

 

The holes are not going to cause a loss of power. A clogged cat will though. It is possible that pieces of the cat broke off and are clogging your muffler, or the cat itself.

 

small holes if there is enough of them could lessen the velocity of exhaust gases exiting the system.

 

I agree with casper. I think you got a plugged cat.