nabit

I have an 850 holley 4150 right now and I want a 950. I see that you can get the main body to make an 850 a 950 but I am not sure if they use the same base plate. Some places list the base plate as a 850/950 plate and others list them separate.

Do the 850 and the 950 4150 holley carbs share the same base plate or not?
also if the plates are the same is this just a simple bolt together thing with changing out the main body or what is all involved?

Thanks!!